The mainstay of the highly-prosperous economy is tourism, accounting for about 80% of GDP. An estimated 10 million people visit each year, drawn by winter sports, a warm summer climate and duty-free goods. The country's banking sector enjoys partial tax-haven status. For more than 700 years Andorra was ruled jointly by the leader of France and the Spanish Bishop of Urgell. The first Andorran Constitution was passed in 1993, establishing parliamentary government. It then joined the United Nations and Council of Europe. The co-princes remain Andorra's heads of state, but the roles are honorary. Andorra is not a member of the EU, but enjoys a special relationship with it and uses the euro.