Thanks to the fact that Tesla does not release monthly sales numbers, we actually don't know precisely how many electric vehicles were sold in the USA during 2013. But Green Car Reports does an excellent job of gathering and extrapolating data, and it calculates that electric vehicle sales were approximately 96,000 for all of 2013, a big jump from 53,000 in 2012.
Monthly sales of electric vehicles now are regularly above 9,000 cars and so are selling at an annual rate above 100,000. Sales in 2014 will almost certainly be higher than in 2013.
But how much higher will be impacted heavily by four factors--the price of gasoline, the deployment of public electric charging stations, pricing of electric vehicles, and the progress in extending electric vehicle range. The pricing of electric vehicles and their range depend substantially on battery advances. Those advances are being made but they are incremental when measured year-to-year.
In sum, 2013 was an important year for electric vehicles that saw more models introduced, more buyers, and better vehicles. The trend is up and 2014 promises to be another year of progress.