Hi:
There is an archived version of the Bomber Command Diary here:
RAF History - Bomber Command 60th Anniversary
It has a day-by-day picture of targets, losses, etc.
It's taken from the "Bomber Command War Diaries" by Martin Middlebrook (I've also mentioned it in the other losses thread). In the appendices, the author says around 60% of Bomber Command became casualties, calculated thus:
Aircrew seeing active service: around 125,000
Killed in action or died as PoWs: 47,268
Killed in flying accidents: 8,195
Killed in ground battles: 37
Total Fatal Casualties: 55,500
Prisoners of War, including many wounded: 9,838
Wounded in aircraft, returned from ops: 4,200
Wounded in accidents flying or ground: 4,203
Total Wounded, other than PoWs: 8,403
Total Aircrew Casualties 73,741
You have to bear in mind that casualties were incurred at widely differing rates during the conflict. Here's a graph I whipped up from data off the Bomber Command website I mentioned in the other thread:
As you can see, for the better part of three years, overall losses (Failed to Return, lost in operational accidents) ran at about 5%. However, as about half of the total sorties were made in the last year of the war when the Luftwaffe had been nearly overwhelmed, overall rates end up being lower, around 2.7%.
Hope this helps.