Source: United States Geological Survey (USGS) Minerals Resources Program
Note: Check source table for details and footnotes
| Year | Production | Unit of Measure | % Change |
| 2003 | 50 | Thousand metric tons | NA |
| 2004 | 50 | Thousand metric tons | 0.00 % |
| 2005 | 119.831001281738 | Thousand metric tons | 139.66 % |
| 2006 | 711.398986816406 | Thousand metric tons | 493.67 % |
| 2007 | 671.335998535156 | Thousand metric tons | -5.63 % |
| 2008 | 702.018005371094 | Thousand metric tons | 4.57 % |
| 2009 | 700 | Thousand metric tons | -0.29 % |
