and 18. The school leaving age is 16, after which students may choose to remain at school and study further qualifications. A small number of students at certain private schools may follow the English system and study towards GCSEs and A and AS-Levels instead. There are fifteen Scottish universities, some of which are amongst the oldest in the world. The four universities founded before the end of the 16th century – the University of St Andrews, the University of Glasgow, the University of Aberdeen and the University of Edinburgh – are collectively known as the ancient universities of Scotland, all of which rank among the 200 best universities in the world in the THE rankings, with Edinburgh placing in the top 50. Scotland had more universities per capita in QS' World University Rankings' top 100 in 2012 than any other nation. The country produces 1% of the world's published research with less than 0.1% of the world's population, and higher education institutions account for 9% of Scotland's service sector exports. Scotland's University Courts are the only bodies in Scotland authorised to award degrees. Tuition fees are handled by the Student Awards Agency Scotland (SAAS), which pays the fees of what it defines as "Young Students". Young Students are defined as those under 25, without children, marriage, civil partnership or cohabiting partner, who have not been outside of full-time education for more than three years. Fees must be paid by those outside the young student definition, typically from £1,200 to £1,800 for undergraduate courses, dependent on year of application and type of qualification. Postgraduate fees can be up to £3,400. The system has been in place since 2007 when graduate endowments were abolished. Labour's education spokesperson Rhona Brankin criticised the Scottish system for failing to address student poverty. Scotland's universities are complemented in the provision of Further and Higher Education by 43 colleges. Colleges offer National Certificates, Higher National Certificates, and Higher National Diplomas. These Group Awards, alongside Scottish Vocational Qualifications, aim to ensure Scotland's population has the appropriate skills and knowledge to meet workplace needs. In 2014, research reported by the Office for National Statistics found that Scotland was the most highly educated country in Europe and among the most well-educated in the world in terms of tertiary education attainment, with roughly 40% of people in Scotland aged 16–64 educated to NVQ level 4 and above. Based on the original