A periodic U.S. Census Bureau report says labor union membership across the country has been declining steadily and in 2015 accounted for fewer than 12 percent of workers — about half what it was in 1983, the first year of the survey. The decline has largely been in private industry. Public-sector union membership has grown slightly and is highest in local governments. Iowa ranks in the middle tier of states for percentage of union workers, although it dropped from 10.7 percent in 2014 to 9.6 percent in 2015. See a slideshow of charts illustrating changes here.