Except as provided by rule adopted under Section 813.304(d) or Section 803.202(a)(2), a member who has service credit in the elected class of membership, is eligible to retire and receive a service retirement annuity if the member:
(1) is at least 60 years old and has 8 years of service credit in that class; or
(2) is at least 50 years old and has 12 years of service credit in that class.