Source: United States Geological Survey (USGS) Minerals Resources Program
Note: Check source table for details and footnotes
| Year | Production | Unit of Measure | % Change |
| 2003 | 15000 | Metric tons | NA |
| 2004 | 23840 | Metric tons | 58.93% |
| 2005 | 13000 | Metric tons | -45.47% |
| 2006 | 16000 | Metric tons | 23.08% |
| 2007 | 20000 | Metric tons | 25.00% |
| 2008 | 25000 | Metric tons | 25.00% |
| 2009 | 25000 | Metric tons | 0.00% |
| 2010 | 23000 | Metric tons | -8.00% |
| 2011 | 23000 | Metric tons | 0.00% |
| 2012 | 24000 | Metric tons | 4.35% |
| 2013 | 24000 | Metric tons | 0.00% |
