Algeria's economy remains dominated by the state, a legacy of the country's socialist post-independence development model. Gradual liberalization since the mid-1990s has opened up more of the economy, but in recent years Algeria has imposed new restrictions on foreign involvement in its economy and largely halted the privatization of state-owned industries. Hydrocarbons have long been the backbone of the economy, accounting for roughly 60% of budget revenues, 30% of GDP, and over 95% of export earnings. Algeria has the eighth-largest reserves of natural gas in the world and is the fourth-largest gas exporter. It ranks 16th in oil reserves. Thanks to strong hydrocarbon revenues, Algeria has a cushion of $150 billion in foreign currency reserves and a large hydrocarbon stabilization fund. In addition, Algeria's external debt is extremely low at about 1% of GDP. Algeria has struggled to develop industries outside of hydrocarbons in part because of high costs and an inert state bureaucracy. The government's efforts to diversify the economy by attracting foreign and domestic investment outside the energy sector have done little to reduce high poverty and youth unemployment rates. In 2010, Algeria began a five-year, $286 billion development program to update the country's infrastructure and provide jobs. The costly program will boost Algeria's economy in 2011 but worsen the country's budget deficit. Long-term economic challenges include diversification from hydrocarbons, relaxing state control of the economy, and providing adequate jobs for younger Algerians.