The Islamic Republic of Iran joined the IsDB in March 1989 and is the 3rd largest shareholder in IsDB's subscribed capital with total amount of ID 4.17 billion (8.25% of total IsDB subscribed capital). The country also holds significant stakes in other IsDB Group entities and is among the top six borrowing clients of the IsDB Group financing. With over 81 million inhabitants, Iran is the world's 18th most-populous country. Comprising a land area of 1,648,195 km2, it is the second- largest country in the Middle East and the 17th-largest in the world. Iran's economy is characterized by a large hydrocarbon sector, small scale agriculture and services sectors, and a noticeable state presence in manufacturing and financial services. Iran ranks second in the world in natural gas reserves and fourth in proven crude oil reserves. Economic activities and Government revenues depend to a larger extent on oil revenues, which makes the Iranian economy facing concentration risk in view of oil price volatility.