"An estimated 30,000 to 40,000 Canadians work in the U.S. under an exemption granted under NAFTA, known as the TN visa." I'm surprised that that number isn't h

"An estimated 30,000 to 40,000 Canadians work in the U.S. under an exemption granted under NAFTA, known as the TN visa." I'm surprised that that number isn't higher.