Source: United States Geological Survey (USGS) Minerals Resources Program
Note: Check source table for details and footnotes
| Year | Production | Unit of Measure | % Change |
| 2002 | 5 | Thousand metric tons | NA |
| 2003 | 13 | Thousand metric tons | 160.00% |
| 2004 | 11 | Thousand metric tons | -15.38% |
| 2005 | 9 | Thousand metric tons | -18.18% |
| 2006 | 7 | Thousand metric tons | -22.22% |
| 2007 | 7.97399997711182 | Thousand metric tons | 13.91% |
| 2008 | 8 | Thousand metric tons | 0.33% |
| 2009 | 30 | Thousand metric tons | 275.00% |
| 2010 | 31 | Thousand metric tons | 3.33% |
| 2011 | 13 | Thousand metric tons | -58.06% |
| 2012 | 117.072998046875 | Thousand metric tons | 800.56% |
| 2013 | 132 | Thousand metric tons | 12.75% |
