Since 2003, hospital operating costs have increased less than the national average, according to a study done by actuarial and consulting company Milliman Inc. for the Greater Milwaukee Business Foundation on Health. Aurora Health Care showed the sharpest decline compared with other health care systems, with operating costs now in line with the market average. The study also found that operating costs for area hospitals increased about 10 percent from 2003 through 2006--roughly 4 to 5 percentage points below the national average. A 2005 study by the U.S. Government Accountability Office found that the Milwaukee area had the fifth-highest hospital costs in the country.