In computing the number of required off-street parking spaces, the following rules shall be applied:
(A) Floor area shall mean the gross floor area of the specific use, excluding any floor or portion thereof used for parking as herein defined.
(B) Where fractional spaces result, the number of parking spaces required shall be the nearest whole number.
(C) Whenever a building or use constructed or established after August 3, 1995, is changed or enlarged in floor area, number of employees, number of dwelling units, seating capacity or otherwise, parking spaces shall be provided on the basis of the enlargement or change.
(D) Whenever a building or use existing prior to August 3, 1995, is reconstructed or is enlarged to the extent of 20% or more in floor area, said building or use in its entirety shall than and thereafter comply with the parking requirements set forth herein. Any enlargement or change in use of less than 20% of the gross floor area shall be provided with parking based on the enlargement or change.