Notwithstanding the provisions of section 4575(d)(1) of this title, and except as otherwise provided in subparagraph (C) of such subsection (d)(1), the aggregate of gross compensation paid employees in the office of a Senator shall not exceed during each fiscal year $1,012,083 if the population of his State is less than 5,000,000.

Subsection (a) shall take effect October 1, 1991.