Source: United States Geological Survey (USGS) Minerals Resources Program
Note: Check source table for details and footnotes
| Year | Production | Unit of Measure | % Change |
| 2003 | 273933 | Metric tons | NA |
| 2004 | 226459 | Metric tons | -17.33% |
| 2005 | 82118 | Metric tons | -63.74% |
| 2006 | 447184 | Metric tons | 444.56% |
| 2007 | 220389 | Metric tons | -50.72% |
| 2008 | 395299 | Metric tons | 79.36% |
| 2009 | 394955 | Metric tons | -0.09% |
