Source: United States Geological Survey (USGS) Minerals Resources Program
Note: Check source table for details and footnotes
| Year | Production | Unit of Measure | % Change |
| 2003 | 33.2099990844727 | Thousand metric tons | NA |
| 2004 | 46.9000015258789 | Thousand metric tons | 41.22 % |
| 2005 | 229 | Thousand metric tons | 388.27 % |
| 2006 | 392 | Thousand metric tons | 71.18 % |
| 2007 | 628 | Thousand metric tons | 60.20 % |
| 2008 | 650 | Thousand metric tons | 3.50 % |
| 2009 | 700 | Thousand metric tons | 7.69 % |
