It took 200,000 years for humans to reach 3 billion in number. It took 40 years for the next 3 billion.
11
Intelligent men tend to be more sexually faithful.
31
Men laugh longer, louder, and more often than women.
61
Roughly a quarter of the world's people live in China.
50
15 percent of Americans secretly bite their toes.
57
It is estimated that at any one time, 0.7% of the world's population are drunk.
90