"Helping a billion people connect is amazing, humbling, and by far the thing I am most proud of in my life," says Mark Zuckerberg.

Justin Sullivan/Getty Images

arly Thursday, Facebook announced it had reached the 1 billion user mark, a mere eight years after the wildly popular social network launched. The milestone was actually reached on Sept. 14, but founder and CEO Mark Zuckerberg waited until this morning to announce the achievement on NBC's Today. (Watch the video below.) "Thank you for giving me and my little team the honor of serving you," Zuckerberg wrote later. "Helping a billion people connect is amazing, humbling, and by far the thing I am most proud of in my life." Here, a look at the historic milestone, by the numbers: 

More than 1 billion
Facebook users worldwide

1 out of 7
People in the world who use Facebook

314 million
Population of the U.S.

1.3 billion
Population of China

2
Countries that have more citizens than Facebook has users (China and India)

824 million
The world's population in 1750

1,000
Engineers working on Facebook. That works out to 1 million users per engineer

1.13 trillion
"Likes" since the Facebook feature launched in February 2009

140.3 billion
Friend connections

219 billion
Photos uploaded

17 billion
Location-tagged posts, including check-ins

62.6 million
Songs played using Facebook-compatible music apps like Spotify

210,000
Years of music played on Facebook

22
Average age of someone who joins Facebook

500 million
Twitter users worldwide

845 million
Facebook users when the company first filed for its initial public offering in February

500 million
Facebook users two years ago

50 million
Facebook users five years ago

25 million
Facebook users six years ago

600 million
People who use Facebook on their mobile phones, up 48 million from June. That's a "key metric" for the company looking forward, says Zack Whittaker at CNET, as people in developing countries use their phones as their primary internet connection.

Sources: Facebook, All Things D, Bloomberg Businessweek, CNET, Los Angeles Times, Stats.gov