, the Syrian economy relies upon inherently unreliable revenue sources such as dwindling customs and income taxes which are heavily bolstered by lines of credit from Iran. Iran is believed to spend between $6 billion and US$20 billion a year on Syria during the Syrian Civil War. The Syrian economy has contracted 60% and the Syrian pound has lost 80% of its value, with the economy becoming part state-owned and part war economy. At the outset of the ongoing Syrian Civil War, Syria was classified by the World Bank as a "lower middle income country." In 2010, Syria remained dependent on the oil and agriculture sectors. The oil sector provided about 40% of export earnings. Proven offshore expeditions have indicated that large sums of oil exist on the Mediterranean Sea floor between Syria and Cyprus. The agriculture sector contributes to about 20% of GDP and 20% of employment. Oil reserves are expected to decrease in the coming years and Syria has already become a net oil importer. Since the civil war began, the economy shrank by 35%, and the Syrian pound has fallen to one-sixth of its prewar value. The government increasingly relies on credit from Iran, Russia and China.