(a) The electors may authorize the township board to levy a tax (at a rate of not more than 0.15% of the value, as equalized and assessed by the Department of Revenue, of all taxable property in the township) for the sole and exclusive purpose of providing services to senior citizens under Article 220 including, but not limited to, the construction, maintenance, repair, and operation of a senior citizens center. If the board desires to levy the tax, it shall order a referendum on the proposition to be held at an election in accordance with the general election law. The board shall certify the proposition to the proper election officials, who shall submit the proposition to the voters at an election in accordance with the general election law. If a majority of the votes cast on the proposition is in favor of the proposition, the board may annually levy the tax in addition to any other taxes and not subject to the tax rate limitations set forth in Article 235 of this Act, but subject to the extension limitations in the Property Tax Extension Limitation Law of the Property Tax Code.
     (b) If the township board of any township authorized to levy a tax under this Section pursuant to a referendum held before January 1, 1987, desires to increase the maximum rate of the tax to 0.15% of the value, as equalized and assessed by the Department of Revenue, of all taxable property in the township, it shall order a referendum on that proposition to be held at an election in accordance with the general election law. The board shall certify the proposition to the proper election officials, who shall submit the proposition to the voters at an election in accordance with the general election law. If a majority of the votes cast on the proposition is in favor of the proposition, the maximum tax rate shall be so increased.