Here's the cliff notes:
“But in 1998, researchers were finally able to do what Isabel Briggs Myers could not: an actual population study. The study was based on a national representative sample – 3,009 randomly selected individuals – which, through weighting of underrepresented groups, was made to approximate the distribution of the 1990 U.S. Census. The findings were clear: introverts and extroverts are equally represented in the population.” (emphasis in original)
Here's the cliff notes: “But in 1998, researchers were finally able to do what Isabel Briggs Myers could not: an actual population study. The study was based on a national representative sample – 3,009 randomly selected individuals – which, through weighting of underrepresented groups, was made to approximate the distribution of the 1990 U.S. Census. The findings were clear: introverts and extroverts are equally represented in the population.” (emphasis in original)