10. SARPA recalculates child support in accordance with the rules for the determination of child support prescribed under the Code of Civil Procedure (chapter C-25) and in accordance with the terms prescribed by government regulation. The child support is recalculated as of the date of the application for recalculation, taking into account the changes in the income of either parent that was used to determine the support being recalculated. However, if the income increased before the date of the application, SARPA recalculates the child support as of a date not earlier than one year prior to the date of the application; regardless of the number of increases, the child support is recalculated for each period in which the income increased, only taking into account the increase relating to that period.