People living to older ages account for much of the recent increase. The global median age, now 32, has been rising in a trend expected to continue toward 39 in 2060.
In a milestone for humanity, the global population hit 8 billion on Tuesday after having added a billion people in the last 12 years, with India on the cusp of overtaking China as the world's most populous country next year.
The discovery of Hepatitis C virus revealed the cause of the remaining cases of chronic hepatitis and made possible blood tests and new medicines that have saved millions of lives.
