The director shall provide to West Virginia citizens who are sixty-two years of age or older, and who document residency and age by a valid West Virginia driver's license, a fifty percent reduction in campground rental fees for each campsite to be used exclusively by said eligible camper: Provided, That the fifty percent reduction in campground rental fees shall only apply to those rentals occurring during the period of time beginning on the day after Labor Day and ending four days prior to Memorial day.