Those who manage Washington County’s defined-benefit pension plan hoped to see the value of the fund rise by at least 17.7 percent last year.

They bested their benchmark by 2.3 percent, it was announced Thursday at a quarterly meeting of the county Retirement Board. The total value of the portfolio at the end of 2013 was $134,640,553, and it increased by another $300,000 as of Thursday morning.

Among a large group of defined-benefit public pension plans, the Washington County retirement fund performed in the top 25 percent of every quarter and in the top 10 percent for the past seven years, according to a report by Lee Martin of the Peirce Park Group of Chester County.

The strong returns have the potential to lower the annual taxpayer contribution to the county employees’ pension fund, but county officials won’t have the exact figure until May.

Last year, taxpayers’ contribution was $4,059,517. About $1,873,900 of the annual retirement contribution is either reimbursable through state or federal grants or paid from a fund that sustains itself through its operations, leaving roughly $2,185,617 that was paid from county property tax dollars.

By state law passed in 1971, the county is required to provide a defined-benefit plan to its employees.

Washington County is steadily rebounding from a precipitous drop of 25 percent in its portfolio in 2008 as the housing bubble burst and sent markets into a tailspin.

Washington County has 1,100 employees who contribute 7 percent of their earnings to their pension plans.

County Treasurer Francis King asked for a financial forecast for 2014.

“Lower expectations all around,” Martin replied.