Kerala's economy depends significantly on emigrants working in foreign countries, mainly in the Arab states of the Persian Gulf, and the remittances annually contribute more than a fifth of GSDP. The state witnessed significant emigration during the Gulf Boom of the 1970s and early 1980s. In 2008, the Persian Gulf countries together had a Keralite population of more than 2.5 million, who sent home annually a sum of 6.81 billion, which is the highest among Indian states and more than 15.13% of remittances to India in 2008. In 2012, Kerala still received the highest remittances of all states: US$11.3 billion, which was nearly 16% of the US$71 billion remittances to the country. In 2015, NRI deposits in Kerala have soared to over , amounting to one-sixth of all the money deposited in NRI accounts, which comes to about . A study commissioned by the Kerala State Planning Board, suggested that the state look for other reliable sources of income, instead of relying on remittances to finance its expenditure. A decline of about 300,000 in the number of emigrants from the state was recorded during the period between 2013 and 2018. The total remittances received by the emigrants stood at in the year 2018. According to a study done in 2013, was the total amount paid to migrant labourers in the state every year.