That’s because Russia didn’t have its revolution till the XXth century - at which point its death rate accelerated considerably......
Of course executions and cutting off heads isn’t the only way to kill people an, even though Russia didn’t have the death penalty, that didn’t stop it killing people. The following, for example, is an example of mass deportation and genocide copied in later years by Stalin......
https://historynewsnetwork.org/article/151025