refinery in Pančevo (capacity of 4.8 million tons) is one of the most modern oil-refineries in Europe; it also operates network of 334 filling stations in Serbia (74% of domestic market) and additional 36 stations in Bosnia and Herzegovina, 31 in Bulgaria, and 28 in Romania. There are 155 kilometers of crude oil pipelines connecting Pančevo and Novi Sad refineries as a part of trans-national Adria oil pipeline. Serbia is heavily dependent on foreign sources of natural gas, with only 17% coming from domestic production (totalling 491 million cubic meters in 2012) and the rest is imported, mainly from Russia (via gas pipelines that run through Ukraine and Hungary). Srbijagas, public company, operates the natural gas transportation system which comprise 3,177 kilometers of trunk and regional natural gas pipelines and a 450 million cubic meter underground gas storage facility at Banatski Dvor. Industry The industry is the economy sector which was hardest hit by the UN sanctions and trade embargo and NATO bombing during the 1990s and transition to market economy during the 2000s. The industrial output saw dramatic downsizing: in 2013 it was expected to be only a half of that of 1989. Main industrial sectors include: automotive, mining, non-ferrous metals, food-processing, electronics, pharmaceuticals, clothes. Serbia has 14 free economic zones as of September 2017, in which many foreign direct investments are realized. Automotive industry (with Fiat Chrysler Automobiles as a forebearer) is dominated by cluster located in Kragujevac and its vicinity, and contributes to export with about $2 billion. Country is a leading steel producer in the wider region of South Central Europe and had production of nearly 2 million tons of raw steel in 2018, coming entirely from Smederevo steel mill, owned by the Chinese Hesteel. Serbia's mining industry is comparatively strong: Serbia is the 18th largest producer of coal (7th in the Europe) extracted from large deposits in Kolubara and Kostolac basins; it is also world's 23rd largest (3rd in Europe) producer of copper which is extracted by Zijin Bor Copper, a large copper mining company, acquired by Chinese Zijin Mining in 2018; significant gold extraction is developed around Majdanpek. Serbia notably manufactures intel smartphones named Tesla smartphones. Food industry is well known both regionally and internationally and is one of the strong points of the economy. Some of the international brand-names established production in Serbia: PepsiCo and Nestlé in food-processing sector; Coca-Cola (Belgrade), Heineken (Novi