Out of the 5,318,531 total dead in German military about 4.3 million died on the eastern front. So the ratio is closer to 80%. The Eastern Front was exception brutally with mass atrocities committed on both side including poor conditions for prisoners and killing of POWs so even if one surrenders they still have a high mortality rate.

(Rüdiger Overmans, Deutsche militärische Verluste im Zweiten) Weltkrieg. Oldenbourg 2000)