More in U.S. thriving, fewer struggling WASHINGTON, June 17 (UPI) -- The percentage of U.S. adults who say they are thriving rose since February and is now on par with the high of 54.2 percent last January, a survey indicates. In fact, in May the Gallup Economic Confidence Index registered its best monthly reading since January 2008, when the recession began. The Gallup-Healthways Well-Being Index, which tracks well-being in the United States, asked 30,252 U.S. adults last month if they were thriving, struggling or suffering. The survey participants rated their current and future lives on a ladder scale with steps numbered from 0 to 10 based on the Cantril Self-Anchoring Striving Scale. Those who rated their present life a 7 or higher and their live in five years an 8 or higher were classified as thriving, while those who rated both dimensions a 4 or lower were considered suffering. Respondents whose ratings fall in between were considered struggling, Gallup said. In May, 54 percent of U.S. adults rated their lives highly enough to be considered thriving last month, while 42.6 percent were considered struggling. In the beginning in 2009, the percentage of those in the United States who said they were thriving reached a low point of 42 percent. In May, 3.4 percent of U.S. adults said they were suffering, down from 4 percent last fall. The survey has a margin of error of 1 percentage point.