Labor union membership remained relatively unchanged in the construction industry last year, representing 13 percent (nearly 1.1 million workers) of the total construction industry workforce in 2006 (8.44 million workers), compared to 13.1 percent in 2005. Those represented by unions (members as well as nonmembers covered by a union contract) were 13.6 percent of the total workforce, compared to 13.8 percent in 2005.