1. About 8 million of the 15.3 million union members in 2009 belonged to unions affiliated with the AFL-CIO; another 6 million belonged to 7 unions loosely federated under the name Change to Win. The rest were members of other independent unions. About 12.3 percent of U.S. wage and salary workers in 2009 were union members, with government employees having the highest unionization rates. As an occupation, public school teachers have the highest rate of unionization—38 percent.