 The market of hybrid electric vehicles in the United States is the second largest in the world after Japan with cumulative sales of 5.4 million units through December 2019.The 3 million mark was achieved in October 2013, and 4 million in April 2016.Sales of hybrid vehicles in the U.S. began to decline following the financial crisis of 2007–08, and after a short recovery, began to decline again in 2014 due to low gasoline prices, and had a small rebound in 2019.