Happy International Left-Handers Day! Here are nine facts to celebrate lefties

Photos: 10 celeb lefties for International Left Handers Day

2. The unofficial holiday was launched in 1992 by the Left-Handers Club in the United Kingdom.

3. Left-handed people make up about 10% of the world’s population.

4. At least four of the past seven presidents have been left-handed: Barack Obama, Bill Clinton, George H.W. Bush and Gerald Ford.

Ronald Reagan also often shows up on the list of lefties even though he wrote with his right hand. Some historians suggest that he was born left-handed but forced to switch as a child, CNN reported.

5. More than 20% of Apollo astronauts were lefties, according to NASA.

6. In a 1996 study, Harvard Medical School researchers found that orthopedic surgeons, librarians and mathematicians were mostly right-handed while attorneys and architects were, as a group, “either the least right-handed or the most left-handed.”

Read: The best and worst things about being left-handed

7. According to a 2014 study, economist Joshua Goodman of Harvard University’s Kennedy School of Government found that lefties’ earnings were 10% to 12% lower than those of right-handed people. But a 2006 paper for the National Bureau of Economic Research, in which economists from Lafayette College and Johns Hopkins University found that “among the college-educated men in our sample, those who report being left-handed earn 15 percent more than those who report being right-handed.”

8. According to the National Institutes of Health, hand preference begins to develop before birth. It becomes increasingly apparent in early childhood and tends to be consistent throughout life.

9. There are a few terms for left-handers: Sinister, Southpaw, Mollydooker, Goofy footed and Cuddy wifter.