(2) The commission shall retain and may destroy the public records described in subsection (1) of this section as follows:
(a) Original examination papers and their markings and original records in commission hearings shall be retained for at least four years and thereafter may be destroyed if microfilmed copies are retained.
(b) Original or microfilmed copies of all other papers, documents and communications shall be retained for at least four years and thereafter may be destroyed. [1959 c.252 §13]