Source: United States Geological Survey (USGS) Minerals Resources Program
Note: Check source table for details and footnotes
| Year | Production | Unit of Measure | % Change |
| 2003 | 50000 | Metric tons | NA |
| 2004 | 140000 | Metric tons | 180.00% |
| 2005 | 120000 | Metric tons | -14.29% |
| 2006 | 135000 | Metric tons | 12.50% |
| 2007 | 140000 | Metric tons | 3.70% |
| 2008 | 140000 | Metric tons | 0.00% |
| 2009 | 130000 | Metric tons | -7.14% |
