I took your advice, updated my statistics,  and read the year end report from the California New Car Dealers Association. (http://www.cncda.org/Auto_Outlook.asp)

The numbers are quite clear.  BEV sales in California increased year-over-year (typically by ~17%) and now have 2% market share.  PHEV sales declined in 2015 but made up lost ground and exceeded 2014 sales to regain 1.6% market share. That was due to 2015 sales of the best selling GM Volt stalling in anticipation of the cheaper, longer range 2016 model.  

Light vehicle registrations plateaued at 2 million units and are forecast to drop in 2017. On the other hand, I fully expect EV sales to grow with the next generation of affordable >200 mile EVs like the GM Bolt for 2017, Tesla model 3 in 2018, the next Nissan LEAF.