The economy of Saudi Arabia is the largest in the Middle East and the eighteenth largest in the world. A permanent and founding member of the OPEC, Saudi Arabia is also a member of the G20 forum as one of the world's largest economies. Saudi Arabia reportedly has the third most valuable natural resource reserves in the world, mostly petroleum and natural gas. The kingdom has the second-largest proven petroleum reserves, and the fourth-largest measured natural gas reserves. Saudi Arabia is currently the largest exporter of petroleum in the world, which sees it occasionally referred to as a Petro State in Western media. Other major parts of the economy include refining and chemical manufacturing from the oil reserves, much of which is vertically integrated in the state-owned enterprise, Saudi Aramco. The economy of Saudi Arabia functions as a petrostate, and the country plays a prominent role in the OPEC. In 2016, the Saudi government launched its Saudi Vision 2030 program to reduce its dependency on oil and diversify its economic resources. In the first quarter of 2019, Saudi Arabia's budget had its first surplus since 2016. This surplus of $10.10 billion was achieved due to an increase in oil and non-oil revenues. Economic overview The following table shows the main economic indicators in 1980–2021 (with IMF staff estimates in 2022–2027). Inflation under 5% is in green. Saudi oil reserves are the second largest in the world (after Brazilian-Venezuelan Oil Reserves), and Saudi Arabia is the world's leading oil exporter and second-largest oil producer. Proven reserves, according to figures provided by the Saudi government, are estimated to be , which is about one-quarter of the world oil reserves. Petroleum in Saudi Arabia is not only plentiful but also located under pressure close to the earth's surface, which makes it less expensive and more profitable to extract compared to other places. The petroleum sector accounts for roughly 87% of Saudi budget revenues, 90% of export earnings, and 42% of GDP. Saudi Arabia's oil reserves and production are largely managed by the state-owned corporation Saudi Aramco. Another 40% of the GDP comes from the private sector. An estimated 7.5 (2013) million foreigners work legally in Saudi Arabia and play a crucial role in developing the Saudi economy; for example, in the oil and service sectors. The government has been encouraging the growth of the private sector for many years to decrease the kingdom's