A fifth of the 100 largest U.S. public pensions have crossed the 90% funded threshold. : The funded status of the 100 biggest public defined benefit pension plans in the U.S. grew by $60 billion in the fourth quarter, the result of robust equity returns in 2017, Milliman Inc., a consulting and actuarial firm, reported Friday. These plans, which comprise Milliman’s Public Pension Funding Index, had investment returns of 3.2%, with a spread ranging from 1.6% to 4.3%.