When a building or structure undergoes a decrease in gross floor area, seating capacity, number of employees or other unit of measurement, the available off-street parking and loading facilities may be also reduced accordingly: provided, that existing off-street parking or loading facilities may be so decreased only when the parking or loading facilities remaining would at least equal or exceed the off-street parking or loading requirements resulting from application of the provisions of these standards to the entire building, activity or structure as modified. (Ord. 1743 § 1 (part), 1999)