The majority of the fastest-selling used cars in 2017 were alternative fuel vehicles.

Looking at the top three fastest-selling used vehicles for the year, No. 1 was an electric vehicle, No. 2 was a plug-in hybrid, and No. 3 was a traditional combustion engine vehicle.

Among the top 10 fastest-selling used cars in 2017, six were alternative fuel, while four were gasoline engine vehicles.

This is based on a survey conducted by iSeeCars.com — an automotive data and research company — that analyzed over 2.1 million late-model used vehicles from January 2017 to August 2017. The survey found that the average used car takes somewhere around 33.4 days to sell. The cars on its top 10 list, however, sold within 22.2 to 26.1 days.

The full list, in descending order, includes the FIAT 500e; BMW i3; Lexus IS 200t; Toyota Plug-in Hybrid; Hyundai Veloster Turbo; Nissan Leaf; Scion FR-S; Mercedes-Benz GLC; Ford Fusion Energi; and Tesla Model S.

The No. 1 vehicle on that list, the FIAT 500e, took dealers an average of 22.2 days to sell while No. 10 on the list, the Tesla Model S, took an average of 26.1 days to sell. The number of days it took to sell the other vehicles on the list fell within at range.

One factor that may have contributed to the FIAT 500e’s position is its low price point. It’s low price makes buying it an easier proposition for consumers, and the fact that it’s price continues to fall also helps it.

Similarly the BMW i3 offers one of the lowest price points for a used luxury vehicle.