Commencing with benefit years beginning on or after January 28, 1971, services performed subsequent to September 30, 1969 in the employ of this state or any of its wholly owned instrumentalities or jointly owned instrumentalities of this state and another state or this state and one or more of its political subdivisions shall be deemed services in employment unless such services are excluded from the term employment by RCW
50.44.040.
The state shall make payments in lieu of contributions with respect to benefits attributable to such employment as provided with respect to nonprofit organizations in subsections (2) and (3) of RCW
50.44.060: PROVIDED, HOWEVER, That for weeks of unemployment beginning after January 1, 1979, the state shall pay in addition to the full amount of regular and additional benefits so attributable the full amount of extended benefits so attributable: PROVIDED, FURTHER, That no payment will be required from the state until the expiration of the twelve-month period following the end of the biennium in which the benefits attributable to such employment were paid. The amount of this payment shall include an amount equal to the amount of interest that would have been realized for the benefit of the unemployment compensation trust fund had such payments been received within thirty days after the day of the quarterly billing provided for in RCW
50.44.060(2)(a).