Israel has a technologically advanced free market economy. Cut diamonds, high-technology equipment, and pharmaceuticals are among its leading exports. Its major imports include crude oil, grains, raw materials, and military equipment. Israel usually posts sizable trade deficits, which are offset by tourism and other service exports, as well as significant foreign investment inflows. Between 2004 and 2013, growth averaged nearly 5% per year, led by exports. The global financial crisis of 2008-09 spurred a brief recession in Israel, but the country entered the crisis with solid fundamentals, following years of prudent fiscal policy and a resilient banking sector. Israel's economy also weathered the 2011 Arab Spring because strong trade ties outside the Middle East insulated the economy from spillover effects. Slowing domestic and international demand and decreased investment resulting from Israel’s uncertain security situation reduced GDP growth to an average of roughly 2.8% per year during the period 2014-17. Natural gas fields discovered off Israel's coast since 2009 have brightened Israel's energy security outlook. The Tamar and Leviathan fields were some of the world's largest offshore natural gas finds in the last decade. Political and regulatory issues have delayed the development of the massive Leviathan field, but production from Tamar provided a 0.8% boost to Israel's GDP in 2013 and a 0.3% boost in 2014. One of the most carbon intense OECD countries, Israel generates about 57% of its power from coal and only 2.6% from renewable sources. Income inequality and high housing and commodity prices continue to be a concern for many Israelis. Israel's income inequality and poverty rates are among the highest of OECD countries, and there is a broad perception among the public that a small number of "tycoons" have a cartel-like grip over the major parts of the economy. Government officials have called for reforms to boost the housing supply and to increase competition in the banking sector to address these public grievances. Despite calls for reforms, the restricted housing supply continues to impact younger Israelis seeking to purchase homes. Tariffs and non-tariff barriers, coupled with guaranteed prices and customs tariffs for farmers kept food prices high in 2016. Private consumption is expected to drive growth through 2018, with consumers benefitting from low inflation and a strong currency. In the long term, Israel faces structural issues including low labor participation rates for its fastest growing social segments - the ultraorthodox and Arab-Israeli communities. Also, Israel's progressive, globally competitive, knowledge-based technology sector employs only about 8% of the workforce, with the rest mostly employed in manufacturing and services - sectors which face downward wage pressures from global competition. Expenditures on educational institutions remain low compared to most other OECD countries with similar GDP per capita.