It may well compare with bowling if you look at the number of injuries per participant, but where bowling injuries might be things like sprains, strains, and smashed toes, they probably don't get many drownings, pulmonary expansion injuries, or embolysms. How many bowlers ever had to spend the day in emergency decompression? Do bowlers need their own rescue insurance companies?
I'm sure there are lots of available statistics, but what are you looking for? deaths per participant? Hospitilizations? Accidents of any sort? per participant hour? by location?
I've heard it said that your odds of being attacked by a shark are less than of being hit by lightning... sure, if you live on a farm in the Midwest. Is this also true of surfers in Florida? This statistic is based on incidents out of the population in general. You need to be mindful of the sample population you're interested in (for example) if you want the stats to be meaningful.
If you want to check out quantitative analysis of relative safety, make sure the numbers describe what they seem to.