all grades of education in Warsaw is almost 500,000 (29.2% of the city population; 2002). The number of university students is over 280,000. Most of the reputable universities are public, but in recent years there has also been an upsurge in the number of private universities. The University of Warsaw was established in 1816, when the partitions of Poland separated Warsaw from the oldest and most influential Polish academic center, in Kraków. Warsaw University of Technology is the second academic school of technology in the country, and one of the largest in East-Central Europe. Other institutions for higher education include the Medical University of Warsaw, the largest medical school in Poland and one of the most prestigious; the National Defence University, the highest military academic institution in Poland; the Fryderyk Chopin University of Music, the oldest and largest music school in Poland and one of the largest in Europe; the Warsaw School of Economics, the oldest and most renowned economic university in the country; the Warsaw University of Life Sciences, the largest agricultural university, founded in 1818; and the University of Social Sciences and Humanities, the first private secular university in the country. Warsaw has numerous libraries, many of which contain vast collections of historic documents. The most important library in terms of historic document collections is the National Library of Poland. The library holds 8.2 million volumes in its collection. Formed in 1928, it sees itself as a successor to the Załuski Library, the biggest in Poland and one of the first and biggest libraries in the world. Another important library – the University Library, founded in 1816, is home to over two million items. The building was designed by architects Marek Budzyński and Zbigniew Badowski and opened on 15 December 1999. It is surrounded by green. The University Library garden, designed by Irena Bajerska, was opened on 12 June 2002. It is one of the largest roof gardens in Europe with an area of more than , and plants covering . As the university garden it is open to the public every day. Transport Warsaw is a considerable transport hub linking Western, Central and Eastern Europe. The city has a good network of buses and a continuously expanding perpendicular metro running north to south and east to west. The tram system is one of the biggest in Europe, with a total length of . As a result of