Spain. 39% of Andorran children attend Andorran schools, 33% attend French schools, and 28% Spanish schools. University of Andorra The Universitat d'Andorra (UdA) is the state public university and is the only university in Andorra. It was established in 1997. The university provides first-level degrees in nursing, computer science, business administration, and educational sciences, in addition to higher professional education courses. The only two graduate schools in Andorra are the Nursing School and the School of Computer Science, the latter having a PhD programme. Virtual Studies Centre The geographical complexity of the country as well as the small number of students prevents the University of Andorra from developing a full academic programme, and it serves principally as a centre for virtual studies, connected to Spanish and French universities. The Virtual Studies Centre (Centre d'Estudis Virtuals) at the university runs approximately 20 different academic degrees at both undergraduate and postgraduate levels in fields including tourism, law, Catalan philology, humanities, psychology, political sciences, audiovisual communication, telecommunications engineering, and East Asia studies. The centre also runs various postgraduate programmes and continuing-education courses for professionals. Transport Until the 20th century, Andorra had very limited transport links to the outside world, and development of the country was affected by its physical isolation. Even now, the nearest major airports at Toulouse and Barcelona are both three hours' drive from Andorra. Andorra has a road network of , of which is unpaved. The two main roads out of Andorra la Vella are the CG-1 to the Spanish border near Sant Julià de Lòria, and the CG-2 to the French border via the Envalira Tunnel near El Pas de la Casa. Bus services cover all metropolitan areas and many rural communities, with services on most major routes running half-hourly or more frequently during peak travel times. There are frequent long-distance bus services from Andorra to Barcelona and Toulouse, plus a daily tour from the former city. Bus services mostly are run by private companies, but some local ones are operated by the government. There are no airports for fixed-wing aircraft within Andorra's borders but there are, however, heliports in La Massana (Camí Heliport), Arinsal and Escaldes-Engordany with commercial helicopter services and an airport located in the neighbouring Spanish comarca of Alt Urgell, south of the Andorran-Spanish border. Since July 2015, Andorra–La Seu d'Urgell Airport has operated commercial flights to Madrid and Palma de Mallorca, and is the main