]  According to the International Monetary Fund, Sri Lanka's GDP in terms of purchasing power parity is the second most highest in the South Asian region in terms of per capita income. In the 19th and 20th centuries, Sri Lanka became a plantation economy famous for its production and export of cinnamon, rubber, and Ceylon tea, which remains a trademark national export. The development of modern ports under British rule raised the strategic importance of the island as a centre of trade. From 1948 to 1977, socialism strongly influenced the government's economic policies. Colonial plantations were dismantled, industries were nationalised, and a welfare state established. In 1977, the free market economy was introduced to the country incorporating privatisation, deregulation, and the promotion of private enterprise. While the production and export of tea, rubber, coffee, sugar, and other commodities remain important, industrialisation has increased the importance of food processing, textiles, telecommunications, and finance. The country's main economic sectors are tourism, tea export, clothing, rice production, and other agricultural products. In addition to these economic sectors, overseas employment, especially in the Middle East, contributes substantially in foreign exchange.  , the service sector makes up 60% of GDP, the industrial sector 28%, and the agriculture sector 12%. The private sector accounts for 85% of the economy. China, India and the United States are Sri Lanka's largest trading partners. Economic disparities exist between the provinces with the Western Province contributing 45.1% of the GDP and the Southern Province and the Central Province contributing 10.7% and 10%, respectively. With the end of the war, the Northern Province reported a record 22.9% GDP growth in 2010. The per capita income of Sri Lanka has doubled since 2005. During the same period, poverty has dropped from 15.2% to 7.6%, unemployment rate has dropped from 7.2% to 4.9%, market capitalisation of the Colombo Stock Exchange has quadrupled and the budget deficit has doubled. Over 90% of the households in Sri Lanka are electrified. 87.3% of the population have access to safe drinking water and 39% have access to pipe-borne water. Income inequality has also dropped in recent years, indicated by a Gini coefficient of 0.36 in 2010. Sri Lanka's cellular subscriber base has shown a staggering 550% growth from 2005 to 2010. Sri Lanka was the first country in the South Asian region to introduce 3G, 3.5G (HSDPA), 3.75G (HSUPA) and 4G (LTE) mobile telecommunication technologies.