Prior to the reformation the Christian population had expanded and contracted several times due in part to plagues and conquest. The number is valid. However, even if, for arguments sake, the number were reduced to 89% or 79% the point is still valid.
Prior to the Reformation the population of Europe (the only place with substantial numbers of Christians at the time) ranged from roughly 30 million to 100 million. Just in the 20th Century alone there have been billions of non-Catholic Christians. Your 99% figure cannot be correct.
However, even if, for arguments sake, the number were reduced to 89% or 79% the point is still valid.
While I agree that your overall point is valid...time for another nitpick! Catholics who died unaware of the Theory of Evolution (which includes every one of them who died before the mid-19th Century) don't count, so he's technically not calling them idiots, only the billions who have lived since then.
The Catholic Church didn’t even really come into existence until sometime in the 300’s AD.
There were churches all across the known world before then, so all those Christians need to be not counted.
Not every Christian during the churches heyday belonged to the Catholic Church and I doubt there’s any way of knowing how many that would be.
The Protestant Reformation began in 1517 some 500 years ago. Al those people need to be considered in the category of Christian outside the Catholic Church. That leaves the Catholic Church about 1200 years of preeminence and easily 800 years of either not existing or having competition.
Then there’s the presumption that everyone who is a Catholic is by default a Christian. Does that include people who didn’t care, who didn’t want to be, who refused to live like Catholics? Those who flaunted religious living? Are Catholics Christians by default simply because of the name they bear, regardless of their beliefs, lifestyle, or behavior?
Considering those figures, and that much of the time that Catholic Church was in power, Europe was being devastated by war and plague, how do you arrive at the percentage that Catholics comprise 99% of the Christians who ever lived?
As you consider yourself a scientist and no doubt consider accuracy and evidence to be important, please back up your contention about your statement in a way befitting a scientist.