Source: United States Geological Survey (USGS) Minerals Resources Program
Note: Check source table for details and footnotes
| Year | Production | Unit of Measure | % Change |
| 2003 | 26 | Thousand metric tons | NA |
| 2004 | 27 | Thousand metric tons | 3.85% |
| 2005 | 1.47599995136261 | Thousand metric tons | -94.53% |
| 2006 | 2.77999997138977 | Thousand metric tons | 88.35% |
| 2007 | 4.03200006484985 | Thousand metric tons | 45.04% |
| 2008 | 1.05900001525879 | Thousand metric tons | -73.74% |
| 2009 | 1.20000004768372 | Thousand metric tons | 13.31% |
| 2010 | 1 | Thousand metric tons | -16.67% |
| 2011 | 0.899999976158142 | Thousand metric tons | -10.00% |
| 2012 | 1 | Thousand metric tons | 11.11% |
