This document is about an abstract of the 1999 Form 5500 Annual Reports, which provide data on private pension plans in the United States. It covers the number of plans, participants, assets, contributions, and benefits for various types of pension plans, including defined benefit, defined contribution, and 401(k) plans. The report highlights key trends in the private pension system, such as the continued shift towards 401(k) plans and the increasing role of participant contributions.