ANY WW2 Historians here??

I retired from an aerospace extrusion manufacturing mill; we sold various profiles to a business in Colorado Springs called West Pac Restorations that restored WWII aircraft. Very cool place to visit and see them rebuilding and fabricating parts. One interesting comment I remember hearing was that there were more casualties among Air Corps than Marine Corps during the war. I heard somewhere that until the Mustang became available for bomber escort it was statistically impossible for a bomber crew to fly 25 missions over Europe without being shot down.