IDC expects the mobile worker population to increase from more than 650 mln worldwide in 2004, to more than 850 mln in 2009, representing more than one-quarter of the global workforce. The United States had the highest percentage of mobile workers in its workforce in 2004, and is expected to reach over 70% mobile workforce penetration by the end of the forecast period, thereby making the US the most mobile-enabled workforce across the five regions.