What was the percentage of bystanders in World War 2?

what was the percentage of bystanders who did what?

percent is a measure of proportion, there needs to be another reference point.

do you mean of the world's population?

do you mean only of those involved in the Holocaust?

but then you say World War II, so do you mean 'which countries were neutral in World War II?'

the question is impossible to answer as it is.