(1) “Income” means all income from whatever source derived including, but not limited to, realized capital gains and, in their entirety, pension, annuity, retirement and social security benefits.

(2) “Income tax year” means the 12-month period for which the property owner files a federal personal income tax return or, if no such return is filed, the calendar year.

(3) “Municipality” means any incorporated town or city of this State.

(4) “Resident” means one legally domiciled within the municipality for the period required by this chapter. Mere seasonal or temporary residence within the municipality, of whatever duration, shall not constitute domicile within the municipality for the purposes of this chapter. Absence from the municipality for a period of 12 months shall be prima facie evidence of abandonment of domicile in the municipality. The burden of establishing legal domicile within the municipality shall be upon the property owner.