Mathwizurd.com is created by David Witten, a mathematics and computer science student at Stanford University. For more information, see the "About" page.
In 1989, there were 7.2 million passports in circulation, whereas the U.S. population was 246.8 million, or 2.9%. In 2019, there are 146 million passports in circulation with a population of 327 million, or 44.6%. So, what happened?
In 2007, the United States required passports to travel to Mexico, Canada, and the Caribbean, thus causing a dramatic increase in