theres a wiki page on combat losses which gives a breakdown from multiple sources although it is a little out of date. unfortunately the (reasonably) exact number is probs only really known by Russian AF Command.
This comment made me decide to go look up casualty rates in the global war on terror. Grim stuff - ours are decidedly better at killing instead of dying, but it's still a massive catastrophe whenever young men decide it's fine and normal to go to war.