The EV market in 2018 is shaping up to come close to 2.00% of all car sales. Sales in California should end up at about 10% of all new vehicle purchases for 2018 (1 out of 10 sales).
The last 3 months of 2018 for California averaged well above 10%. and at this rate, California could “cross the EV chasm” (16% of new vehicle sales) at some point during 2020.
Trends in the US often start in California, expand to other Western states and/or Northeastern states, and then fill in eventually in the Midwest and South. This same pattern is occurring with sales of EVs in the US and is creating in essence "green versus brown states".