Whether sighted with photo evidence or not, logically, the number of J15 should be at least:-
1) #01 to #24 sighted = 24 aircraft (six zhongdui 中队 X 4 aircraft)
2) #30 to #35 sighted = 6 aircraft (two zhongdui x 4 aircraft = 8, i.e. #30 to # 37)
3) #60 to #72 sighted = 13 aircraft (three zhongdui x 4 aircraft + 1 ), OR possibly 4 zhongdui X 4 = 16 aircraft (#60 to #76).
One zhongdui 中队 consist of 4 aircraft.
So existing stock of J15 inclusive of aircraft not yet sighted by photo evidence, should be at least 46 (nine zhongdui 中队), for training and deployment on Liaoning, Shandong and land based training centre.
This assumption is based on that all zhongdui are at full strength, and delivery of new aircraft are in batches that are at X times 4 units each.