Sections 27A-13-18 to 27A-13-20 , inclusive, shall determine patient eligibility for contributions by the county of residency under § 27A-13-16 , except that time spent in a state institution shall not be counted in determining the matter of residency. Source: SL 1964, ch 104 , § 4 (6); SDCL, § 27-9-10; SL 1975, ch 181 , § 123; SL 1976, ch 173 , § 29.