I was surprised by the Iran number so I looked into it. The death toll represents over 20% of Iran's population at the time. The number apparently is a high estimate of everyone who died in Iran during the time period. There was a major famine happening then as well as outbreaks of cholera, typhus, and plague. It would be difficult to tease apart the number of deaths caused by the Spanish flu.
Good point, I changed the number to be about halfway between the lowest and highest estimate. Although this is likely still too high, I could not find a better approximation.
https://en.wikipedia.org/wiki/Persian_famine_of_1917-1919