According to official census data, Soviet Union had around 168 million people in 1939, and around 196 million in 1941 (annexation of Baltic states and part of Poland). Germany (Third Reich) had around 80 million. But, after operation Barbarossa started, Soviet Union lost huge part of its territory, including major cities like Kiev, Minks, Smolensk etc ...
Therefore, population available for conscription and any kind of mobilization(work in industry, agriculture etc) was reduced. What was effective available population in various stages of war? I'm especially interested in December 1941 and October 1942, because Germans held biggest swaths of Soviet territory at that time.