Retirement Plan Participation and Contributions: Trends from 1998 to 2006
"The U.S. Census Bureau periodically collects information from individuals about their participation in employer-sponsored retirement plans. The most recent such survey was conducted from February through May of 2006. After extensive review and editing by the Census Bureau, the survey data files were released to the public in November 2008. This CRS report presents a summary of the data and a comparison of the results of the 2006 survey with similar surveys that the Census Bureau conducted in 1998 and 2003."