Source: United States Geological Survey (USGS) Minerals Resources Program
Note: Check source table for details and footnotes
| Year | Production | Unit of Measure | % Change |
| 2003 | 35000 | Metric tons | NA |
| 2004 | 86608 | Metric tons | 147.45% |
| 2005 | 72867 | Metric tons | -15.87% |
| 2006 | 93091 | Metric tons | 27.75% |
| 2007 | 90000 | Metric tons | -3.32% |
| 2008 | 90000 | Metric tons | 0.00% |
