Thailand, officially the Kingdom of Thailand and formerly known as Siam, is a country in the center of the Indochina Peninsula in Southeast Asia. With a total area of about 513,000 square kilometers, Thailand is the world's 50th largest country. It is the world's 20th most populous country, with about 66 million people. Thailand is a constitutional monarchy and has alternated between parliamentary democracy and military junta for decades, most recently in a coup in May 2014 by the National Council for Peace and Order. Its capital and most populous city is Bangkok. It is bordered to the north by Myanmar and Laos, to the east by Laos and Cambodia, to the south by the Gulf of Thailand and Malaysia, and to the west by the Andaman Sea and the southern tip of Myanmar. Its maritime borders include Vietnam in the Gulf of Thailand to the southeast, and Indonesia and India in the Andaman Sea to the southwest. The Thai economy is the 20th largest in the world by GDP in public-private partnership and the 27th largest by nominal GDP. It became a modern industrial country and a major exporter in the 1990s. Manufacturing, agriculture and tourism are the leading sectors of the economy.