OK. However I think the comparison might have a better balance if based on age. Not many 20+ year old EVs and yet plenty of 20+ year old gassers on the road mixed in with the burn statistics.
So if only vehicles of the same age were compared it would be a better look at what is the risk of spontaneous combustion.
I do make the assumption that older machinery has more problems. This assumption may not be valid.
A lot of EV fires seem to be from high speed single vehicle accidents. Again probably biased based on media reporting.