Source: United States Geological Survey (USGS) Minerals Resources Program
Note: Check source table for details and footnotes
| Year | Production | Unit of Measure | % Change |
| 2003 | 16 | Thousand metric tons | NA |
| 2004 | 2 | Thousand metric tons | -87.50 % |
| 2005 | 2.19300007820129 | Thousand metric tons | 9.65 % |
| 2006 | 3.46000003814697 | Thousand metric tons | 57.77 % |
| 2007 | 2.35999989509583 | Thousand metric tons | -31.79 % |
| 2008 | 2.53999996185303 | Thousand metric tons | 7.63 % |
| 2009 | 2.44000005722046 | Thousand metric tons | -3.94 % |
| 2010 | 2.20000004768372 | Thousand metric tons | -9.84 % |
| 2011 | 5.15000009536743 | Thousand metric tons | 134.09 % |
| 2012 | 5 | Thousand metric tons | -2.91 % |
