(1) Henceforth a total of not more than four years of service outside of the state shall be credited to a member who establishes or reestablishes credit for out-of-state public school employment in this state subsequent to July 1, 1961. Foreign public school teaching service shall be creditable as out-of-state service.
(2) No out-of-state service credit shall be established or reestablished subsequent to July 1, 1964, except that a member who has been granted official leave of absence by his or her employer may, upon return to public school service in this state, establish out-of-state membership service credit, within the limitations of this section and conditioned upon satisfactory proof and upon contributions to the member reserve, for public school service rendered in another state or in another country.
(3) No member who establishes out-of-state service credit after July 1, 1947, shall at retirement for pension payment purposes be allowed credit for out-of-state service in excess of the number of years credit which he or she shall have earned in the public schools of the state of Washington.