The board shall retain the services of an independent contractor, not involved in the investment process, to make a report to the board not less than every four years on the investment performance results of the assets of the retirement funds. Source: SL 1974, ch 35 , § 72; SL 2016, ch 31 , § 25; SDCL § 3-12-118 ; SL 2019, ch 22 , § 1.