There are several factors at
There are several factors at play.
1) low gas prices are impacting sales
2) Low inventory levels for the Nissan Leaf and BMW i3 have no doubt caused a drop in sales
2a) The new 2016 Nissan Leaf was released late in 2015 and inventory has not built up.
2b) Rumor - BMW will be increasing the battery capacity of the i3 by 50%. Inventory levels are low which seems to support the rumor.
3) The Chevy Bolt is announced to release by end of year. There will be a lot of people who hold out for a year to get double the range for the same price (including me). The Tesla Model 3 reservations are opening up this month and some will wait 2+ years for their next BEV.
4) The very small market segment willing to pay $37K for an 84 mile range electric car has reached saturation and BEV sales won't recover until the next generation cars with double range for the same price are released (Nissan Leaf v2, Chevy Bolt, Tesla Model3)