As Fran points out, this is a tough one. I have done a lot of research on WWII troopships, but have never come across any definitive records that point to the total number of ships lost.

The US Navy reported 20 Navy owned troop ships sunk, but many troop transports were owned and operated by the Army, although they had Navy Armed Guard Units on board. Many of the Army records were destroyed in 1951. Most records that are available only list numbers of ships in convoys and total number sunk, but don't break the sinkings down. It would probably require massive research to compile an accurate list.

I have done research on roughly 200 troopships, but I have not tabulated casualties. However, my recollection is that there were actually very small number of sinkings.

If I come across anything reasonable, I will be happy to pass it along.

Rick