Also worthy of note is that the data is often incomplete for NTSB investigated accidents, and if it involves someone with multiple ratings (FW, RW, etc), then it may not break that into appropriate bits.
Flight instruction for low time instructors is not considered, etc.
And the number of ratings and licenses held is also not considered - I worked on a case where the pilot had nearly every rating known to the FAA, but not the magic number supposedly required by the insurance company. As he had passed all the necessary checkrides, it was relatively easy to prove he had demonstrated the same level of competency that someone with more hours would. (and the actual cause of the accident wasn't even considered, nor was whether more experience would have made any difference).
Accidents and statistics should be considered mutually exclusive things unless you can see all the data.