Source: United States Geological Survey (USGS) Minerals Resources Program
Note: Check source table for details and footnotes
| Year | Production | Unit of Measure | % Change |
| 2002 | 0.899999976158142 | Thousand metric tons | NA |
| 2003 | 0.699999988079071 | Thousand metric tons | -22.22% |
| 2004 | 0.5 | Thousand metric tons | -28.57% |
| 2008 | 0.699999988079071 | Thousand metric tons | 40.00% |
| 2009 | 7 | Thousand metric tons | 900.00% |
| 2010 | 11 | Thousand metric tons | 57.14% |
| 2011 | 11 | Thousand metric tons | 0.00% |
| 2012 | 11 | Thousand metric tons | 0.00% |