Botswana, officially the Republic of Botswana, is a landlocked country in Southern Africa. Formerly known as the British protectorate of Bechuanaland, Botswana took on its new name after becoming independent on 30 September 1966. Botswana is said to have the best perceived corruption ranking in Africa since at least 1998. Hard to believe, but Botswana is currently Africa's oldest continuous democracy. Topographically flat, the Kalahari Desert covers around 70% of the 581,730 km² (224,610 square miles) land. It has a population of just over 2 million people, making Botswana one of the most sparsely populated countries in the world. The capital and largest city, Gaborone is home to only 10% of the population. In the 1960s it had a GDP per capita of about US$70 per year, but since then has transformed itself into one of the world's fastest-growing economies. The economy is sustained by mining, cattle, and tourism. Today, Botswana has an astonishing GDP per capita of about $18,825 per year as of 2015, which is one of the highest in Africa, a growth of almost 27,000% from 1960. The currency is the Pula (translated as rain) divided into 100 Thebe (raindrops). The first coins were issued to commemorate the independence in 1966, while first circulation coins were only issued in 1976, 10 years after independence.