Does anyone know of a resource for finding the average retirment plan earnings? I am trying to help a lawyer determine what a reasonable rate of return would have been on plan assets for years going back to 1987.

Try the Department of Labor PWBA Private Pension Plan Bulletin. In Spring 1999 the Abstract of 1995 Form 5500 Annual Reports was released. Table E24 shows the aggregate return on plans with 100 or more participants for years 1985 to 1995.