The American Customer Satisfaction Index (ACSI) measures the attitudes of consumers in several different categories, including PCs and online Web sites, on a scale from zero to 100. For the second quarter of 2004, the PC industry posted a score of 74, which represents an improvement of 2.8% compared to 2003 and a level the industry hasn't achieved in four years. Apple Computer and Gateway recorded the largest improvements in customer satisfaction. With a score of 81, Apple's customers are the most satisfied of any other PC vendor measured in this index. Dell's customers were only slightly less satisfied than Apple's, according to the index. The PC market share leader received a score of 79.