True, it's not with 100% certainty; people are complicated beings. That why I said "more accurate". However, some people could be really good at hiding that they have kids from other people. Example: Bob's in a relationship (or married) with no kids...but Bob has a secret family with kids with another lover (or spouse) on the side.
List of childless people (famous and less famous) and with some descriptions why they decided to be so in their own words:
A childless person can still serve as a parental figure to or foster parent of others and leave behind an enduring legacy regardless. It's more accurate to say a selfish person makes a poor leader while a selfless one makes an awesome leader. Also it matters more what spiritual quality of kids you raise over the physical quantity of them.
Probably this: 100% - 84% = 16% <- real approval