The vast crowds of day laborers who populated a stretch of South Dixie Highway south of the city have dwindled to a few dozen men. The painters and drywallers who carried Miami’s condo boom have moved on — or home — as the region’s construction industry grinds to a near halt. Long dependent on population growth and construction for its economic health, the Florida construction industry lost 71,900 jobs from September 2007 to September 2008, accounting for more than 62 percent of all the jobs lost in the state. The downturn parallels a property crash that began after the market peaked in late 2005. During the boom, Florida’s unemployment rate ran well below the nation’s, But at 6.6 percent it is now 0.5 percent higher than the U.S. jobless rate.