The disability retirement pension, other than an industrial disability retirement pension, for a member, other than a member who is subject to Section 21424 or 21427, shall be such an amount as with that portion of his or her annuity provided by his or her accumulated normal contributions, shall make his or her disability retirement allowance equal to one of the following:
(a)
Ninety percent of one-fiftieth of his or her final compensation multiplied by the number of years of service credited to
him or her.
(b)
If the disability retirement allowance computed under subdivision (a) does not exceed one-third of his or her final compensation, 90 percent of one-fiftieth of his or her final compensation multiplied by the number of years of service that would be creditable to him or her if his or her service were to continue until attainment by him or her of the age of 60 years, but in that case the retirement allowance shall not exceed one-third of final compensation.
This subdivision is not applicable to members who are not entitled, at the time of retirement, to be credited with at least 10 years of state service.
(c)
If qualified for service retirement, the member shall receive his or her service retirement allowance if that allowance is greater than the disability retirement allowance provided by this section.