 In 1992 about two-thirds of systemwide sales came from U.S. McDonald's, but by 1997 that figure was down to about 51 percent.Similarly, the operating income numbers showed a reduction from about 60 percent of sales derived from the US in 1992 to 42.5 percent in 1997.In the US, the number of units grew from 9,000 in 1991 to 12,500 in 1997, an increase of about 40 percent.