5.3. Where the amount of the contribution of the municipality established under section 1.1 is revised under section 5.1, the amount established under section 1.3 is revised using the following formula:
A × B
A = 4% for the 2012 fiscal year;
8% for the 2013 fiscal year;
12% for the 2014 fiscal year;
15% for every following fiscal year;
B = the amount of the revised contribution of the municipality established under section 5.1.
An amount equal to the difference between the amount calculated under the first paragraph and the amount calculated under section 1.3 is added to or subtracted from the contribution for the following municipal fiscal year, as the case may be. If the municipality no longer receives police services after 1 January of that fiscal year and the amount cannot be added to or subtracted from the contribution, the amount is claimed from or refunded to the municipality, as the case may be. In no case does that amount bear interest.