Looking further Wikipedia has an B-17 article which has the following:
"A third raid on Schweinfurt on 24 February 1944 highlighted what came to be known as "Big Week". With P-51 Mustang and P-47 Thunderbolt fighters (equipped with improved drop tanks to extend their range) escorting the American heavies all the way to and from the targets, only 11 of 231 B-17s were lost. The escort fighters reduced the loss rate to below seven percent, with only 244 B-17s lost in 3500 sorties while taking part in the Big Week raids."
At the bottom of the article under "External Links" is a website of a Sam Hewitt who served in the 15th Air Force 301 Bomber Group who was also a POW but later, June 26th 1944.
Also Goggle "Big Week Raids" for all sorts of information.