A comic may not be the best source out there. But I tend to trust Randall Munroe on his research work and claims. Here's his graph: https://xkcd.com/1732/ http

A comic may not be the best source out there. But I tend to trust Randall Munroe on his research work and claims. Here's his graph: https://xkcd.com/1732/ https://xkcd.com/1732/