of the first Muslim mosque in Australia. Despite the tolerance of all religions, most of the state's original colonists were Christian. Adelaide in particular saw much early Christian activity, with the oldest remaining buildings in the city being churches. It has been known as "the City of Churches" since at least 1872. Education Primary and secondary On 1 January 2009, the school leaving age was raised to 17 (having previously been 15 and then 16). Education is compulsory for all children until age 17, unless they are working or undergoing other training. The majority of students stay on to complete their South Australian Certificate of Education (SACE). School education is the responsibility of the South Australian government, but the public and private education systems are funded jointly by it and the Commonwealth Government. The South Australian Government provides, to schools on a per student basis, 89 percent of the total Government funding while the Commonwealth contributes 11 percent. Since the early 1970s it has been an ongoing controversy that 68 percent of Commonwealth funding (increasing to 75% by 2008) goes to private schools that are attended by 32% of the states students. Private schools often counter this by saying that they receive less State Government funding than public schools, and in 2004 the main private school funding came from the Australian government, not the state government. On 14 June 2013, South Australia became the third Australian state to sign up to the Australian Federal Government's Gonski Reform Program. This will see funding for primary and secondary education to South Australia increased by $1.1 billion before 2019. The academic year in South Australia generally runs from the end of January until mid-December for primary and secondary schools. The SA schools operate on a four-term basis. Schools are closed for the South Australia public holidays. Tertiary There are three public and four private universities in South Australia. The three public universities are the University of Adelaide (established 1874, third oldest in Australia), Flinders University (est. 1966) and the University of South Australia (est. 1991). The four private universities are Torrens University Australia (est. 2013), Carnegie Mellon University - Australia (est. 2006), University College London's School of Energy and Resources (Australia), and Cranfield University. All six have their main campus in the Adelaide metropolitan area: Adelaide and UniSA on North Terrace in the city; CMU, UCL and Cranfield are co-located on Victoria Square