The data I've seen compared vehicles up to 5 years old and is per vehicle, so not normalised by mileage for instance. The rate of fire is considerably lower - around 1/3rd as much.
It's not fair to directly compare all ICE vehicles to battery EVs, because EVs have only been a commercially available product for about 10 years and only in the last 5 or so years have been available in larger numbers from many manufacturers. An old car is a lot more likely to be involved in a fire, especially if poorly maintained. If you compare battery EVs to all available vehicles, the rate is much better, around 1/10th that. Whether that statistic is relevant depends on whether you believe an older EV will become more of a fire risk over time; the biggest hazard is thermal runaway of the battery pack, which could be age-related, but primarily seems to be random chance due to cell shorts.
In the UK I recall seeing many videos of the old Vauxhall Zafiras catching fire... This was not actually Vauxhall's fault per se, but due to cabin fan speed controls being replaced with 3rd party knockoffs (the original controls were notorious for failure and were expensive) which did not have a temperature fuse fitted. If the fan stalled for any reason, the fan resistor would no longer be cooled, leading to a very hot source trapped inside of plastic HVAC vents.