Famous people throughout history? What number are famous.

What percentage of the population are famous. In the past you had to cure a disease or start a war to be famous. Napoleon, Curie, Pasteur and Genghis Khan. when you think about these old type famous people it's very abstract as most don't have any realistic visage. How many of us know what Pasteur looked like?
With modern fame you see too much of their faces. Some even are famous for having a pretty face? There's even different levels of fame. How many people consider Charlie Schultz as famous(never recognize him). Against his creation Snoopy. Then there's a-list famous people like Tom Cruise and Barrack Obama. Most people would recognize them. Maybe fifty percent of the world? (third world countries with no tv?)
How many people who have ever lived are famous. Is it over 25,000? 100,000?