the amount of income tax that has been or is to be collected through withholding on Each Class of Income that formed the basis for calculating that person's amount of taxable gross income for 2006 (if Each Class of Income so used includes occasional income, miscellaneous income or Ad Hoc Income not falling under miscellaneous income, the amount after deducting the amount of income tax that has been or is to be collected through withholding on that income).