This (below) from Hansard. Interesting, but not necessarily illuminating. Just because an electric vehicle was involved in an accident doesn’t mean that the cause of the accident was related to that ‘electricness’. Worth noting that there are about 28,000,000 cars in the UK. Of these about 100,000 are hybrids and around 2,600 fully electric.
Mr Amess: To ask the Secretary of State for Transport what estimate he has made of the number of persons who were (a) killed, (b) seriously injured and (c) slightly injured by plug-in electric and hybrid electric vehicles when operating in electric mode in each of the last two years; and if he will make a statement. 
Stephen Hammond: The number of casualties in reported personal injury road accidents known to involve electric and hybrid electric vehicles for the years 2010 and 2011 were as follows:
Two deaths, 10 serious injuries, and 59 slight injuries in 2010; and one death, 10 serious injuries and 56 slight injuries in 2011.
Hybrid electric vehicles
10 deaths, 72 serious injuries and 576 slight injuries in 2010; and five deaths, 61 serious injuries and 761 slight injuries in 2011.
In both years the number of casualties known to involve electric or hybrid electric vehicles accounted for less than 0.5% of the total number of casualties in reported road accidents in Britain.
The Department refers to DVLA records to determine whether a vehicle involved in an accident has electric or hybrid electric propulsion. This is only possible for British-registered vehicles where a full and accurate vehicle registration mark (VRM) is contained in the police record. This information exists for around three-quarters of vehicles involved in personal injury accidents. There may therefore have been additional accidents involving electric or hybrid electric vehicles that are registered outside Britain, or where the reported VRM was invalid or missing.
The Department does not hold information on whether a vehicle was operating in electric mode at the time of the accident, nor whether the vehicle is of the ‘plug-in’ type.