the plans in the study. The plans continue the trend of growing more mature (that is, having relatively more retired has been essentially flat for the past 13 years, whereas the number of retired and inactive members has increased each year. This increase is also shown with the maturity ratio, which is defined as the number of retired and inactive members compared to the number of active members. Collectively, the 10 largest plans (ranked by liability) cover 36% of the total members, hold 40% of the aggregate assets, and have 39% of the aggregate liability.