men and women live on the same floor, but a few dorms are configured for men and women to live on separate floors (single-gender floors). Several residences are considered theme houses. The Academic, Language, and Culture Houses include EAST (Education and Society Themed House), Hammarskjöld (International Themed House), Haus Mitteleuropa (Central European Themed House), La Casa Italiana (Italian Language and Culture), La Maison Française (French Language and Culture House), Slavianskii Dom (Slavic/East European Themed House), Storey (Human Biology Themed House), and Yost (Spanish Language and Culture). Cross-Cultural Themed Houses include Casa Zapata (Chicano/Latino Theme in Stern Hall), Muwekma-tah-ruk (American Indian/Alaska Native, and Native Hawaiian Themed House), Okada (Asian-American Themed House in Wilbur Hall), and Ujamaa (Black/African-American Themed House in Lagunita Court). Focus Houses include Freshman-Sophomore College (Academic Focus), Branner Hall (Community Service), Kimball (Arts & Performing Arts), Crothers (Global Citizenship), and Toyon (Sophomore Priority). Theme houses predating the current "theme" classification system are Columbae (Social Change Through Nonviolence, since 1970), and Synergy (Exploring Alternatives, since 1972). Co-ops or "Self-Ops" are another housing option. These houses feature cooperative living, where residents and eating associates each contribute work to keep the house running, such as cooking meals or cleaning shared spaces. These houses have unique themes around which their community is centered. Many co-ops are hubs of music, art and philosophy. The co-ops on campus are 576 Alvarado Row (formerly Chi Theta Chi), Columbae, Enchanted Broccoli Forest (EBF), Hammarskjöld, Kairos, Terra (the unofficial LGBT house), and Synergy. Phi Sigma, at 1018 Campus Drive was formerly Phi Sigma Kappa fraternity, but in 1973 became a Self-Op. As of 2015 around 55 percent of the graduate student population lived on campus. First-year graduate students are guaranteed on-campus housing. Stanford also subsidizes off-campus apartments in nearby Palo Alto, Menlo Park, and Mountain View for graduate students who are guaranteed on-campus housing but are unable to live on campus due to a lack of space. Athletics As of 2016 Stanford had 16 male varsity sports and 20 female varsity sports, 19 club sports and about 27 intramural sports In 1930, following a unanimous vote by the executive committee for the Associated Students, the athletic department adopted the mascot "Indian." The Indian symbol and name were dropped by President Richard Lyman in 1972, after objections from Native American students and a vote by the student senate. The sports teams are now officially referred to as the "Stanford