The U.S. new-vehicle market set a new record last year, with deliveries of new passenger cars and light trucks totaling 17.39 million.
The previous record of 17.35 million was set in 2000.
But battery-electric and plug-in hybrid vehicles saw their totals fall slightly, from about 120,000 in 2014 to roughly 115,000 last year.
DON'T MISS: Plug-In Electric Car Sales Continue Rise In 2014, To 118,500 (Jan 2015)
As always, the numbers are somewhat approximate, given the handful of automakers who refuse to say how many plug-in vehicles they delivered in the U.S.
That number includes Tesla Motors, which gives only global deliveries by quarter. It also includes sales data for the Fiat 500e compliance car and the limited-distribution Kia Soul EV.
Unlike some other outlets, Green Car Reports doesn't blend data from third-party sources with manufacturer-supplied delivery figures.
2016 Tesla Model X with 2011 Tesla Roadster Sport, photographed by owner Bonnie Norman
From the top, Tesla likely delivered 25,000 to 26,000 Model S electric luxury sedans in the U.S. last year. The company has said only that its total 2015 deliveries were 50,557.
Its long-delayed Model X electric SUV also squeaked into production, with 208 delivered during the last quarter of the year.
All of the highest-volume plug-in cars saw sales decline last year over the comparable 2014 figures, largely due to the known timing of upgraded 2016 models coming late last year.
ALSO SEE: Plug-In Electric Car Sales For 2013 Near Double Previous Year's (Jan 2014)
Chevrolet delivered 15,393 Volts last year, against 18,805 Volts during 2014. The all-new 2016 Volt, with a range boosted to 53 miles from the previous model's 38 miles, went on sale this past September.
It received rave reviews and won numerous awards (one of them being the Green Car Reports 2016 Best Car To Buy award).
Sales of the Cadillac ELR range-extended luxury coupe fell to 1,024 last year, against 1,310 the previous year.
GM's Pam Fletcher and Josh Tavel accept Green Car Reports 2016 Best Car To Buy award for 2016 Volt
The Chevrolet Spark EV battery-electric minicar, however, more than doubled its sales to 2,629 last year from 1,145 in 2014.
Insiders have suggested that with the green light given to the 200-mile 2017 Chevrolet Bolt EV, which goes into production late this year, Chevy's interest in marketing and promoting the small battery-electric hatchback was renewed.
With a huge spike in Spark EV sales in April through June last year, the little car logged sales that may surpass GM's compliance needs under California's zero-emission vehicle rules.
MORE: Chevrolet Volt: Green Car Reports' Best Car To Buy 2016
Nissan, meanwhile, saw its Leaf sales in the U.S. plummet from a record 30,200 during 2014 to just 17,269 last year.
News of a longer-range Leaf for 2016 was discussed during large parts of last year, and Georgia terminated its $5,000 income-tax credit for buying an electric car.
Those factors, and probably the continued fall in retail gasoline prices, meant that sales of the five-year-old Leaf model slumped.
2016 Nissan Leaf
The 107-mile versions of the 2016 Nissan Leaf are now reaching dealerships, but the all-new second-generation Leaf isn't expected to arrive until the 2018 model year.
That gives the current Leaf just this year to boost its sales, as it may be affected by the launch of the 2017 Chevy Bolt EV roughly a year hence.
The only other plug-in model with U.S. sales in excess of 10,000 units last year was the BMW i3, in both its battery-electric and range-extended REx versions.
2014 BMW i3 REx, scenic New Jersey, Apr 2015 [photo by owner Tom Moloughney]
BMW sold 11,024 i3s last year, against 6,092 in the eight months of 2014 it was on sale. (For May through December last year, i3 sales were 7,937, or 30 percent more than the same period in 2014.)
And the Volkswagen e-Golf delivered a surprisingly high total of 4,232 sales last year, with an especially strong fourth quarter in particular.
Perhaps not coincidentally, that corresponded precisely to the period in which all of Volkswagen's TDI diesel vehicles were pulled off sale after the VW diesel-emission cheating scandal erupted in mid-September.
2012 Toyota Prius Plug-In Hybrid, Catskill Mountains, NY, Oct 2012
The Toyota Prius Plug-In Hybrid--which had sold 12,000 to 13,300 units in 2012, 2013, and 2014--saw sales fall to just 4,191 after production ended last summer.
A plug-in version of the new fourth-generation 2016 Toyota Prius hybrid is expected to be unveiled at an auto show this year as a 2017 model.
Sources suggest it could have 25 to as much as 35 miles of electric range, against the low 11 miles of the previous version.
Both of Ford's plug-in hybrid Energi models saw sales decline last year over their 2014 totals.
The Fusion Energi mid-size sedan fell to 9,750 from 11,550 in 2014, and the C-Max Energi compact tall hatchback declined to 7,591 from 8,433.
2016 Ford Fusion Energi
Finally, the low-volume Honda Accord Plug-In Hybrid sedan made its final bow last year, with only 64 delivered against 449 in 2014.
It is to be supplanted by a new plug-in hybrid model expected to use the underpinnings of the 2017 Honda Clarity hydrogen fuel-cell sedan, which will also spawn an all-electric version as well--sometime in the future.
Low-volume plug-in hybrids
Following those eight higher-volume plug-in cars, there are close to two dozen other models that sell in much smaller volumes.
Among the plug-in hybrids, we've covered the Cadillac ELR and Honda Accord already.
2016 BMW i8
The pricey, sexy BMW i8 gull-wing plug-in hybrid coupe delivered 2,265 sales last year, its first full year on sale.
Not bad for a car that costs $140,000 and up, although--as we've said before--we think it'd sell equally well even if powered by coal and ground-up baby seals.
Porsche, too, has pricey plug-in hybrids; last year it delivered 1,098 Cayenne S e-Hybrid SUVs and another 407 Panamera S e-Hybrid luxury sedans.
And a new entrant, Audi, got its first plug-in hybrid certified at the very end of December, squeaking into the current calendar year with only a couple of selling days.
The Audi A3 e-Tron sold 49 units in December, and with Audi's ambitious goals for the car--and all A3 TDI diesel models pulled off sale as well--we look forward to seeing how it sells this year.
2016 Audi A3 e-Tron Sportback, San Francisco Bay Area, Oct 2015
Small numbers of plug-in hybrids from Mercedes-Benz have also been delivered, likely less than 200 each of the S 550e, ML/GLE 550e, and C 400e.
Similarly, BMW snuck a few low-volume plug-in hybrids onto sale this year, with deliveries of the BMW X5 xDrive 40e starting in 2015.
There's also the Hyundai Sonata Plug-In Hybrid and the Volvo XC90 T8 'Twin Engine' SUV. We'll add precise figures as we track them down.
2015 Chevrolet Spark EV
Low-volume battery electrics
We've covered the Chevy Spark EV above, and among the California compliance cars, sales of both the Honda Fit EV and the Toyota RAV4 EV ended early last year.
That leaves only the Ford Focus Electric, whose 76-mile range is now low for battery-electric cars, though Ford promises a boost to 100 miles or so for 2017.
The four-year-old Focus Electric delivered 1,582 sales last year, down from the 1,964 in 2014 (and the 1,738 in 2013).
As noted, Fiat Chrysler refuses to report sales of the Fiat 500e electric minicar, though its deliveries may have gone as high as 6,000 or more last year.
2015 Kia Soul EV and 2014 Nissan Leaf, at Blink DC fast charger - Fife, WA
Nor will Kia break out the figures for its Soul EV, although the company has apparently been surprised by its popularity. Our guess would be roughly 1,000 units.
With plug-in sales holding at more than 100,000 units a year out of a market exceeding 16 million vehicles, clearly cars with plugs are far from breaking into the mainstream.
The pace of that evolution remains to be seen, although it's worth noting that hybrid cars also had a slow ramp in their first few years.
But as an article in The Detroit News suggests, it remains unclear that there is growing consumer demand for plug-in cars.
And that's even before the challenges that shoppers may encounter at franchised car dealers, whose salespeople may attempt to dissuade them from buying the car they came in to ask about.
Light-duty vehicle type scenario, now-2050 (California Air Resources Board)
But for the moment, it's regulations--both the rising Corporate Average Fuel Economy rules nationally and looming jumps in California's zero-emission vehicle sales numbers--that drive most carmakers to produce and sell low numbers of plug-in vehicles.
Will a second Tesla model, an all-new and longer-range Chevy Volt, and a 107-mile Nissan Leaf boost sales for 2016?
Or will it take a mass-priced 200-mile battery-electric car to expand the market?
Inquiring minds want to know.