The ordinary disability pension shall be computed in the same manner as the service pension based on credited service accrued to the date of disability, subject to the following:
(1) In the case of total disability, the minimum pension shall be 50% of compensation plus 5% of compensation for each dependent during the period of dependency, not to exceed a total of 20% of compensation for all dependents; and
(2) In the case of partial disability, the minimum pension shall be 30% of compensation.