Not less than one-third of the members of each board and commission identified in subsection (b) of § 19a-14 shall be public members. As used in this section and in the sections listed in said subsection, “public member” means an elector of the state who has no substantial financial interest in, is not employed in or by, and is not professionally affiliated with, any industry, profession, occupation, trade or institution regulated or licensed by the board or commission to which he or she is appointed, and who has had no professional affiliation with any such industry, profession, occupation, trade or institution for three years preceding his appointment to the board or commission.