Title IX of the Education Amendments of 1972 states that “[n]o person in the United States shall, on the basis of sex, be excluded from participation in, be denied the benefits of, or be subjected to discrimination under any education program or activity receiving Federal financial assistance.” 20 U.S.C. § 1681(a). Title IX’s implementing regulations require that schools provide “equal athletic opportunity for members of both sexes.” 34 C.F.R. § 106.41(c). Among the factors we consider to determine whether equal opportunities are available to male and female athletes is “[w]hether the selection of sports and levels of competition effectively accommodate the interests and abilities of members of both sexes.” Id. § 106.41(c)(1). In 1979, the Office of Civil Rights of the Department of Health, Education, and Welfare—the precursor to today’s Department of Health & Human Services and Department of Education—published a “Policy Interpretation” of Title IX setting a three-part test to determine whether an institution is complying with the “effective accommodation” requirement:
(1) Whether … participation opportunities for male and female students are provided in numbers substantially proportionate to their respective enrollments; or
(2) Where the members of one sex have been and are underrepresented among … athletes, whether the institution can show a history and continuing practice of program expansion which is demonstrably responsive to the developing interest and abilities of the members of that sex; or
