Source: United States Geological Survey (USGS) Minerals Resources Program
Note: Check source table for details and footnotes
| Year | Production | Unit of Measure | % Change |
| 2002 | 153 | Thousand metric tons | NA |
| 2003 | 22 | Thousand metric tons | -85.62% |
| 2004 | 57 | Thousand metric tons | 159.09% |
| 2005 | 8.5 | Thousand metric tons | -85.09% |
| 2006 | 8.5 | Thousand metric tons | 0.00% |
| 2007 | 8.5 | Thousand metric tons | 0.00% |
| 2008 | 8.5 | Thousand metric tons | 0.00% |
| 2009 | 26.3999996185303 | Thousand metric tons | 210.59% |
| 2010 | 14.6000003814697 | Thousand metric tons | -44.70% |
| 2011 | 11.3000001907349 | Thousand metric tons | -22.60% |
| 2012 | 16 | Thousand metric tons | 41.59% |
| 2013 | 13.6999998092651 | Thousand metric tons | -14.38% |
