I found this interesting from the same world clock web site:
How many people have ever lived on earth?
It was written during the 1970s that 75% of the people who had ever been born were alive at that moment. This was grossly false.
Assuming that we start counting from about 50,000 B.C., the time when modern Homo sapiens appeared on the earth (and not from 700,000 B.C. when the ancestors of Homo sapiens appeared, or several million years ago when hominids were present), taking into account that all population data are a rough estimate, and assuming a constant growth rate applied to each period up to modern times, it has been estimated that a total of approximately 106 billion people have been born since the dawn of the human race, making the population currently alive roughly 6% of all people who have ever lived on planet Earth.
Others have estimated the number of human beings who have ever lived to be anywhere from 45 billion to 125 billion, with most estimates falling into the range of 90 to 110 billion humans.