The General Assembly, upon approval thereof by a vote of not less than three-fourths (3/4ths) of the members elected to each house, may provide that the valuation of real property actually occupied by its owner as a residence who is sixty-five (65) years of age, or older, may be exempt in such amount as may be determined by law, but no greater than the first Twenty Thousand Dollars ($20,000) in value thereof, as a homestead from ad valorem property taxes.