Source: United States Geological Survey (USGS) Minerals Resources Program
Note: Check source table for details and footnotes
| Year | Production | Unit of Measure | % Change |
| 2002 | 25 | Thousand metric tons | NA |
| 2005 | 60 | Thousand metric tons | 140.00 % |
| 2006 | 88.1800003051758 | Thousand metric tons | 46.97 % |
| 2007 | 57.9000015258789 | Thousand metric tons | -34.34 % |
| 2008 | 61.7789993286133 | Thousand metric tons | 6.70 % |
| 2009 | 99 | Thousand metric tons | 60.25 % |
| 2010 | 63 | Thousand metric tons | -36.36 % |
| 2011 | 70 | Thousand metric tons | 11.11 % |
| 2012 | 70 | Thousand metric tons | 0.00 % |
