By now, many people would likely produce the correct answer when asked, Where in the U.S. are electric cars most popular?

That would be California, which last year had almost seven battery-electric and plug-in hybrid cars registered per 1,000 people.

But five other states have more than two plug-in vehicles per 1,000 residents—and we're betting most people couldn't name all five.

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The data comes from the U.S. Department of Energy Office of Energy Efficiency and Renewable Energy, which collated state-by-state electric-car registrations as of the end of 2016.

In a "Fact of the Week" blog post in mid-November, the office wrote the following:

In 2016, there were six states with more than two plug-in vehicles (PEVs) registered per 1,000 people. California had the highest concentration of PEVs with 6.65 PEVs per 1,000 people.

Plug-in electric vehicle registrations by state, 2016 [source: U.S. Department of Energy]

Plug-in electric vehicle registrations by state, 2016 [source: U.S. Department of Energy]

Hawaii had the second highest concentration with nearly four PEVs per 1,000 people followed by Washington and Oregon with about three PEVs per 1,000 people. Vermont and Georgia round out the top six with over two PEVs per 1,000 people.

Mississippi had the lowest concentration of PEVs, but all 50 states and the District of Columbia had at least some PEVs. PEV registrations within a state are influenced by many factors, including state and local incentive programs, charging infrastructure, and fuel pricing.

To summarize: after California, the five states with the highest concentrations of electric cars (in alphabetic order) are Georgia, Hawaii, Oregon, Vermont, and Washington.

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Mississippi, meanwhile, is at the very bottom of the list.

A different set of data that addresses a similar issue was provided by Gearheads.org, which analyzed 1.12 million geotagged tweets from October 18 to November 18 this year.with the hashtag #Tesla.

That period, you may recall, included the reveal of the Tesla Semi and the surprise unveiled of the next-generation Tesla Roadster as well.

Geotagged tweets about Tesla, Oct 18-Nov 18, 2017, mapped by state [analysis: Gearheads.org]

Geotagged tweets about Tesla, Oct 18-Nov 18, 2017, mapped by state [analysis: Gearheads.org]

A remarkable 5.2 percent of all tweets geotagged from the state of California contained the word Tesla, the highest percentage of any state.

In order, Washington, Illinois, Nevada, and Oregon rounded out the top five states with the highest percentages of Tesla tweets.

According to Gearheads representative Ryan Taylor, the tweets broke down as 79 percent male, 21 percent female.

The full set of state-by-state percentages are here: Tesla Geotagged Tweets by Percentage.

Interest in Tesla seems to be concentrated in the West Coast states, with a few exceptions like Illinois, which roughly parallels the electric-car adoption rate data from the DoE.

"Just goes to show," Taylor noted, "we still have some work to do to get the Midwest (except Illinois) and Southern states excited about electric transportation."

[hat tip: Brian Henderson]

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