N.H. Rev. Stat. Ann. § 23:8

Every county shall establish the salary for its register of deeds at a fixed dollar value. Said salaries may not be established either in part or in total as a percentage of fees or other charges or payments collected by said register. Said salaries shall be established not less than biennially by the county convention, upon recommendation of the executive committee. In no case shall the salary of any of said registers of deeds be a lesser amount than the salary which said register was receiving on January 1, 1974.