I don't think that is a good metric, in a couple different ways. First you can't universalize the tax rate of serfs like that, and serfs don't represent all pea

I don't think that is a good metric, in a couple different ways. First you can't universalize the tax rate of serfs like that, and serfs don't represent all peasants/lower classes. We are talking about hundreds of years across a huge area. Different social classes also paid different taxes, a villein's obligation to their lord in a village would be different than a free peasants. Much of what a peasant paid was also in kind, either in the form of crops or work for their lords estate. The "history" in the linked article in uncited, so I am not sure where the author is getting that figure from but at best it represents the lives of a specific group of people, not some statement across centuries and countries.