invasion in 2003 to regain what land they considered historically theirs. Foreign relations Despite being landlocked, the Kurdistan Region pursues a proactive foreign policy, which includes strengthening diplomatic relations with Iran, Russia, United States and Turkey. 29 countries have a diplomatic presence in the Kurdistan Region, while the Kurdistan Region has representative offices in 14 countries. Administrative divisions The Kurdistan Region is divided into four governorates (Parêzga): the governorates of Erbil, Sulaymaniyah, Duhok, and Halabja. Each of these governorates is divided into districts, for a total of 26 districts. Each district is also divided into sub-districts. Each governorate has a capital city, while districts and sub-districts have 'district centers'. Economy The Kurdistan Region has the lowest poverty rates in Iraq and the stronger economy of the Kurdistan Region attracted around 20,000 workers from other parts of Iraq between 2003 and 2005. The number of millionaires in the city of Sulaymaniyah grew from 12 to 2,000 in 2003, reflecting the economic growth. According to some estimates, the debt of the Kurdish government reached $18 billion by January 2016. The economy of Kurdistan is dominated by the oil industry. However, Kurdish officials have since the late 2010s attempted to diversify the economy to mitigate a new economic crisis like the one which hit the region during the fight against ISIL. Major oil export partners include Israel, Italy, France and Greece. Petroleum and mineral resources KRG-controlled parts of Iraqi Kurdistan contain 4 billion barrels of proven oil reserves. However, the KRG has estimated that the region contains around of unproven oil resource. Extraction of these reserves began in 2007. In November 2011, Exxon challenged the Iraqi central government's authority with the signing of oil and gas contracts for exploration rights to six parcels of land in Kurdistan, including one contract in the disputed territories, just east of the Kirkuk mega-field. This act caused Baghdad to threaten to revoke Exxon's contract in its southern fields, most notably the West-Qurna Phase 1 project. Exxon responded by announcing its intention to leave the West-Qurna project. As of July 2007, the Kurdish government solicited foreign companies to invest in 40 new oil sites, with the hope of increasing regional oil production over the following 5 years by a factor of five, to about . Notable companies active in Kurdistan include Exxon, TotalEnergies, Chevron, Talisman Energy, DNO, MOL Group, Genel Energy, Hunt Oil, Gulf Keystone Petroleum, and Marathon