When the amount of funds derived from the tax levied pursuant to Section 21-29-117 is sufficient to care for the requirements and necessities as determined by an actuarial study, the governing authorities of said municipality shall discontinue entirely or reduce the tax rate provided in Section 21-29-117 until such time as financial necessity creates a demand for the reassessment of said tax. It is understood, however, in this connection, that when and if the tax collections as herein provided are discontinued, that said tax shall be reassessed when necessity requires, without the necessity of an election. Each municipality with a disability and relief fund for firemen and policemen shall have prepared an actuarial study of the fund at least every four (4) years and report the findings to the legislature of the State of Mississippi. The first such study shall be filed with the legislature in January, 1980.