I want to test the ability of students to read a passage and answer questions about it. Could you please come up with a good question for the passage "The first half of the 20th century in Russia and the Soviet Union was marked by a succession of wars, famines and other disasters, each accompanied by large-scale population losses. Stephen J. Lee estimates that, by the end of World War II in 1945, the Russian population was about 90 million fewer than it could have been otherwise."? 

How many were lost in wars, famines, and disasters?