Year-end level estimated from DOL, Employee Benefits Security Administration, Private Pension Plan Bulletin: Abstract of Form 5500 Annual Reports, Table C4. Balance Sheet of Pension Plans with 100 or More Participants, Defined Benefit, as Non-interest-bearing cash, adjusted for plans whose fiscal years do not end on December 31 and to include plans with fewer than 100 participants. Data are available with a two-year lag. Series is converted to quarterly and estimated for quarters after last benchmark using data from a sample of plans available by subscription from State Street Analytics and the Independent Consultants Cooperative. The unadjusted flow is the change in the level; data for the most recent ten years show no significant seasonality.