Source: United States Geological Survey (USGS) Minerals Resources Program
Note: Check source table for details and footnotes
| Year | Production | Unit of Measure | % Change |
| 2002 | 725000 | Thousand metric tons | NA |
| 2003 | 862080 | Thousand metric tons | 18.91% |
| 2004 | 970000 | Thousand metric tons | 12.52% |
| 2005 | 1068850 | Thousand metric tons | 10.19% |
| 2006 | 1236770 | Thousand metric tons | 15.71% |
| 2007 | 1361170 | Thousand metric tons | 10.06% |
| 2008 | 1400000 | Thousand metric tons | 2.85% |
| 2009 | 1644000 | Thousand metric tons | 17.43% |
| 2010 | 1822000 | Thousand metric tons | 10.83% |
| 2011 | 2099000 | Thousand metric tons | 15.20% |
| 2012 | 2210000 | Thousand metric tons | 5.29% |
