In December 2010, the first few GM Volts and Nissan Leafs were delivered in the U.S. Sales grew rapidly from 17,813 units in 2011, the first full year of sales, to 118,682 units in 2014, the maximum sales year for plug-ins. For hybrids the maximum sales year was 2013, with 495,685 units shipped that year. Hybrid sales declined in 2014 and declined again in 2015 to 384,404 units sold. What happened? Did plug-ins take the market from hybrids?