The employer's payment under Article II [now Article III beginning at Miss. Code Ann. § 25-11-101 (1972, as amended)] shall be made at present on the basis of 2-1/2[CENT] of wages paid each covered employee during a calendar year from $0 to $6000.
Employer contributions shall be made on the basis of the contribution rates as set forth from time to time by the Board of Trustees and levels of earned compensation as set forth in the statute.
27 Miss. Code. R. 210-13-101