(a) The amount of an individual’s lifetime service credit equals the number of months the individual has served in a hazardous duty position during the individual’s lifetime.
(b) The amount of an individual’s state service credit equals the sum of:
(1) the amount of the individual’s lifetime service credit, as determined under Subsection (a); and
(2) the number of months during the individual’s lifetime that the individual has provided services to the state in a position that is not a hazardous duty position.