Civilian casualty ratio
Some 7 million combatants on both sides are estimated to have died during World War I, along with an estimated 10 million non-combatants, including 6.6 million civilians. The civilian casualty ratio in this estimate would be about 59%. Boris Urlanis notes a lack of data on civilian losses in the Ottoman Empire, but estimates 8.6 million military killed and dead and 6 million civilians killed and dead in the other warring countries. The civilian casualty ratio in this estimate would be about 42%. Most of the civilian fatalities were due to famine, typhus, or Spanish flu rather than combat action. The relatively low ratio of civilian casualties in this war is due to the fact that the front lines on the main battlefront, the Western Front, were static for most of the war, so that civilians were able to avoid the combat zones.
Croatia during World War I
In July 1918, first cases of Spanish flu, which killed more than 20 million people worldwide, were reported in Croatia. On average, 60 people were dying in Zagreb per week. In the most difficult period of the epidemic that number has grown to more than 200 people, with a peak in the second week of December, when the number increased to 264. In less than four months, Spanish flu took 700 lives in Zagreb alone, and probably tens of thousands on the whole Croatian territory. Contemporaries evaluated that nearly 90% of the Croatian population was affected in the second half of 1918. Estimate of 15,000 to 20,000 victims in Croatia should be taken as the lower limit of the number of victims of the epidemic.