These analysis are kinda stupid so dont read too much into it. If 90% of your air force is made up for say Chinese aircraft, then most likely 90% of the crashes would be of Chinese made aircraft. Similarly, if majority of your inventory is or has been Mig-21s, they will also be the majority involved in accidents.
These analysis also dont go into any details behind a crash. The most recent Mig-21 coming down after a bird hit does not make the pilot, plane or the maintenance team scapegoats in trying to lay blame.
This article is just throwing random numbers without there being any concise link or argument being presented on how and why. Do we give a shit how many pilots have died since 1971? Not really. Maybe in the last 2 years? Perhaps more relevant.
Anyways, its just a useless article in general that doesnt add any value aside from making some feel good about themselves and for others to use it random statistics to make $