If you look at the last page of the Service Inquiry into the last Gazelle crash
https://www.gov.uk/government/upload...936_SI_-_2.pdf
You'll see a summary of Gazelle incidents/accidents in EOL training which was compiled about 6 months before the ETPS one so I'm not sure if they included it in the final figures. In total 67 including 4 Cat 4/5 over several decades and 1.1 Million hours of UK military operation. Oh and 12 actual uses of the technique in anger for whatever reason.
I don't know how that compares to the R-22 but I suspect quite well.