Australia has 37 government-funded universities and three private universities, as well as a number of other specialist institutions that provide approved courses at the higher education level. The OECD places Australia among the most expensive nations to attend university. There is a state-based system of vocational training, known as TAFE, and many trades conduct apprenticeships for training new tradespeople. About 58% of Australians aged from 25 to 64 have vocational or tertiary qualifications, and the tertiary graduation rate of 49% is the highest among OECD countries. 30.9% of Australia's population has attained a higher education qualification, which is among the highest percentages in the world.