According to independent sales tracking information from the NPD Group, Wii has become the best-selling video game console in the United States. More than 666,000 Wii consoles sold for the month of June, and nearly 10.9 million Wii consoles have been sold in the United States in the 20 months following its November 2006 launch. The portable Nintendo DS finished as the top-selling U.S. video game system in June, with more than 783,000 units sold. To date, more than 20.8 million Nintendo DS has been sold in the United States.