Well between Ukrainian AA fire and Russia’s stellar record of aviation maintenance, the actual number of available airframes is probably half that…
Read some expert opinions from former USAF members regarding the Russian operation in Syria.
The Russian airforce:
* 40 year old planes
* Built by error prone Soviet factories
* Maintained by crews who pocket 80% of the budget
* Flown by pilots with more vodka than oxygen in their blood
For all these reasons the Russian air force has shown itself very poorly this war.