USAF - loss of airframes in Global War on Terror . . .

The tally of Air Force aircraft lost to date in the Global War on Terror, counting from Sept. 11, 2001, is 65. This includes 23 manned platforms and 42 unmanned aerial vehicles, according to data provided by the service.

Airforce - Magazine

although I don’t know the number of flights completed in that time, I would think that that number of a/c lost is pretty remarkable. Especially those lost in actual combat.