Source: United States Geological Survey (USGS) Minerals Resources Program
Note: Check source table for details and footnotes
| Year | Production | Unit of Measure | % Change |
| 2003 | 11248 | Thousand metric tons | NA |
| 2004 | 1047.80004882813 | Thousand metric tons | -90.68 % |
| 2005 | 1412 | Thousand metric tons | 34.76 % |
| 2006 | 1713.59997558594 | Thousand metric tons | 21.36 % |
| 2007 | 1439 | Thousand metric tons | -16.02 % |
| 2008 | 918.5 | Thousand metric tons | -36.17 % |
| 2009 | 828 | Thousand metric tons | -9.85 % |
