Source: United States Geological Survey (USGS) Minerals Resources Program
Note: Check source table for details and footnotes
| Year | Production | Unit of Measure | % Change |
| 2003 | 4374 | Metric tons | NA |
| 2004 | 2993 | Metric tons | -31.57% |
| 2005 | 4201 | Metric tons | 40.36% |
| 2006 | 1961 | Metric tons | -53.32% |
| 2007 | 2104 | Metric tons | 7.29% |
| 2008 | 2108 | Metric tons | 0.19% |
| 2009 | 1202 | Metric tons | -42.98% |
| 2010 | 1364 | Metric tons | 13.48% |
| 2011 | 349 | Metric tons | -74.41% |
| 2012 | 730 | Metric tons | 109.17% |
| 2013 | 750 | Metric tons | 2.74% |
