In the United States, community colleges are primarily two-year public institutions of tertiary education. Community colleges offer undergraduate education in the form of an associate degree. In addition community colleges also offer remedial education, GEDs, high school diplomas, technical diplomas and academic certificates, and in rare cases, a limited number of 4-year bachelor's degrees. After graduating from a community college, some students transfer to a four-year college or university to continue their studies leading to a bachelor's degree. Community college is tuition-free for selected students in 47 states, often under the name College Promise. Most community college instructors have advanced degrees but serve as part-time low wage employees. Community college enrollment has declined every year since 2010. According to the National Student Clearinghouse, the total decline in enrollment from 2010 to 2020 was more than 2.2 million students. The largest enrollment drop occurred in 2020, the latest year surveyed. Before the 1970s, community colleges were often referred to as junior colleges, and that term is still used at some institutions and for athletics, specifically the NJCAA. However, the term "junior college" is now usually used to characterize private two-year institutions. The term "community college" has evolved to describe publicly funded two-year institutions. The main national advocacy organization for community colleges, which was founded in 1920 as the "American Association of Junior Colleges", changed its name in 1992 to the "American Association of Community Colleges". Cohen and Brawer noted other names: city college, county college (in New Jersey), and branch campus. Other common components of the school name include vocational, technical, adult education and technical institute. Nicknames include "democracy's college" and "opportunity college". In several California cities, community colleges are often called "city colleges", since they are municipally funded and designed to serve the needs of the residents of the city in which they are situated.