Ülkeler Milyon ton % S. Arabistan .....519......................13.2 Rusya.................470......................12.0 ABD....................307......................7.8 İran.....................205......................5.2 Meksika.............188......................4.8 Çin......................183......................4.7 Venezuela .........162......................4.1 Kanada..............143......................3.6 Norveç ..............139......................3.5 Nijerya ...............133......................3.4 Diğer ülkeler ....1.474 ..................37.7 Dünya ...............3.923...................100.0
