If you needed additional evidence that the funding status of U.S. corporate pension plans saw a lousy 2014, Towers Watson has it.

The aggregate funded status last year of the Towers Watson Pension 100 — sponsors of the 100 largest U.S. pension programs among U.S. publicly traded organizations, ranked by pension benefit obligations at year-end 2013 — dropped from 89 percent to 81 percent.

As others have reported, lower interest rates, coupled with new mortality assumptions, managed to boost liabilities high enough to cancel out most of the returns on assets during the year.

Also read: Discount rate plays havoc with corporate pensions