Measures (IMAGE) University of Wisconsin-Madison Caption Three measures of the level of manufacturing business activity show a long-term decline over the last few decades. A change in 1998 in how businesses are classified creates a jump in the numbers that year. Credit Nathan Seltzer Usage Restrictions None License Licensed content Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.