(1) Participating employers shall pay the certified contribution rates to the office to maintain this system on a financially and actuarially sound basis.
(2) For purposes of determining contribution rates, this system is divided into two levels according to participating employers as follows:
(a) Level A includes the state, its independent agencies, independent entities, public corporations, and other instrumentalities, all participating educational institutions, and all other participating employers whose activities are associated with participating educational institutions.
(b) Level B includes all other participating employers in this system.