(1) Effective January 1, 1986, the monetary amounts established in this act for registration and reporting thresholds and for penalties shall be adjusted as of January 1 pursuant to the percentage increase or decrease in the Detroit consumer price index—all items. The adjustment for 1986 shall be made by comparing the Detroit consumer price index for June, 1981 to the corresponding Detroit consumer price index for August, 1985. The resultant percentage change shall then be multiplied by the monetary amounts established in this act on the effective date of this section. These results shall be rounded up to the nearest dollar and added to the amounts established by this act which are $100.00 or less, and rounded up to the nearest $25.00 and added to the amounts established by this act which are more than $100.00, which shall then be the new amounts for 1986.

    (2) Effective January 1, 1987 and each year thereafter, the monetary amounts established in this act for registration and reporting thresholds and for penalties shall be adjusted each January 1 pursuant to the annual average percentage increase or decrease in the Detroit consumer price index—all items. The adjustment for each year shall be made by comparing the percentage increase or decrease in the Detroit consumer price index for the preceding August by the corresponding Detroit consumer price index—all items 1 year earlier. The resultant percentage change shall then be multiplied by the affected monetary amounts. These results shall be rounded up to the nearest dollar for amounts established on the effective date of this section which are $100.00 or less, and rounded up to the nearest $25.00 for amounts established on the effective date of this section which are more than $100.00, and added to or subtracted from the current monetary amounts as previously adjusted by this section which shall be the new amounts for that year.

    (3) The adjustments shall apply only to expenditures or violations occurring after the date of the adjusting of the amounts.

    (4) The adjusted amounts shall be determined and announced by the secretary of state on or before December 15 of each year and shall be provided to all persons requesting the adjusted amounts.

    (5) If the index is unavailable, the secretary of state shall make a reasonable approximation.