Brian--Terry Ray Wagner's " American Combat Planes " ( the first book I ever bought ,in 1961) has tables for statistics , fighters and bombers in Europe (presumably including the Mediterranean).
No doubt his figures will vary with other published material but they are certainly a good guide.........
B-17 sorties 291,508, lost in combat 4,688 = 1.61 per 100 sorties (by my reckoning)
B-24 sorties 226,775, lost in combat 3,626 = same loss rate.
Interestingly the fighter with the lowest lost rate was not the one you would expect...
the P-39, 107 losses in 30,547 sorties or 0.35 per 100 sorties.
Highest rate was the P-38, 1,758 from 129,849 sorties , or 1.4 per 100.
for comparison, the premier RAF heavy bomber the Lancaster ---in night raids on GERMANY ---lost 2,508 from 83,881 dispatched, a rate of 3.02 per 100.
Out of 7,374 built, 2687 were missing on ops by day & night----or 36.4 %.
Most in one night was 96, the Nuremberg raid of 30/31 March 1944. Nick