Source: United States Geological Survey (USGS) Minerals Resources Program
Note: Check source table for details and footnotes
| Year | Production | Unit of Measure | % Change |
| 2003 | 4200 | Thousand metric tons | NA |
| 2004 | 5900 | Thousand metric tons | 40.48 % |
| 2005 | 138 | Thousand metric tons | -97.66 % |
| 2006 | 120 | Thousand metric tons | -13.04 % |
| 2007 | 117 | Thousand metric tons | -2.50 % |
| 2008 | 100 | Thousand metric tons | -14.53 % |
| 2009 | 290 | Thousand metric tons | 190.00 % |
