Source: United States Geological Survey (USGS) Minerals Resources Program
Note: Check source table for details and footnotes
| Year | Production | Unit of Measure | % Change |
| 2002 | 90 | Thousand metric tons | NA |
| 2003 | 100 | Thousand metric tons | 11.11% |
| 2004 | 110 | Thousand metric tons | 10.00% |
| 2005 | 120 | Thousand metric tons | 9.09% |
| 2006 | 130 | Thousand metric tons | 8.33% |
| 2007 | 150 | Thousand metric tons | 15.38% |
| 2008 | 200 | Thousand metric tons | 33.33% |
| 2009 | 200 | Thousand metric tons | 0.00% |
| 2010 | 150 | Thousand metric tons | -25.00% |
| 2011 | 100 | Thousand metric tons | -33.33% |
| 2012 | 50 | Thousand metric tons | -50.00% |
| 2013 | 100 | Thousand metric tons | 100.00% |
