Hi Parsifal,
Well, I think the real question is - what conclusions do you draw from the evidence you presented?
Maybe it's just that the "total Flak collapse" (inexact quote) gave me wrong ideas about what you actually meant to convey.
The total sortie loss ratio for 8th Air Force bombers appears to have been 4 - 7 % until October 1943, 3 - 4 % until April 1944, and 1 - 2 % until December 1944. What we would need would be the information which part of these losses was due to flak.
(My data is from the manual to "Secret Weapons of the Luftwaffe", but I think I've seen similar statistics in the Strategic Bombing Survey.)
Regards,
Henning (HoHun)