The Australian prime minister, Billy Hughes, wrote to the British prime minister, Lloyd George, "You have assured us that you cannot get better terms. I much regret it, and hope even now that some way may be found of securing agreement for demanding reparation commensurate with the tremendous sacrifices made by the British Empire and her Allies." Australia received £5,571,720 war reparations, but the direct cost of the war to Australia had been £376,993,052, and, by the mid-1930s, repatriation pensions, war gratuities, interest and sinking fund charges were £831,280,947. Of about 416,000 Australians who served, about 60,000 were killed and another 152,000 were wounded. Diseases flourished in the chaotic wartime conditions. In 1914 alone, louse-borne epidemic typhus killed 200,000 in Serbia. From 1918 to 1922, Russia had about 25 million infections and 3 million deaths from epidemic typhus. In 1923, 13 million Russians contracted malaria, a sharp increase from the pre-war years. In addition, a major influenza epidemic spread around the world. Overall, the 1918 flu pandemic killed at least 50 million people. The social disruption and widespread violence of the Russian Revolution of 1917 and the ensuing Russian Civil War sparked more than 2,000 pogroms in the former Russian Empire, mostly in Ukraine. An estimated 60,000-200,000 civilian Jews were killed in the atrocities. In the aftermath of World War I, Greece fought against Turkish nationalists led by Mustafa Kemal, a war that eventually resulted in a massive population exchange between the two countries under the Treaty of Lausanne. According to various sources, several hundred thousand Greeks died during this period, which was tied in with the Greek Genocide.
Question: In a span of how many years did 3 million people perish from epidemic typhus?
Answer: 4