Source: United States Geological Survey (USGS) Minerals Resources Program
Note: Check source table for details and footnotes
| Year | Production | Unit of Measure | % Change |
| 2002 | 3695 | Metric tons | NA |
| 2003 | 2552 | Metric tons | -30.93% |
| 2004 | 1240 | Metric tons | -51.41% |
| 2007 | 300 | Metric tons | -75.81% |
| 2008 | 2986 | Metric tons | 895.33% |
| 2009 | 2380 | Metric tons | -20.29% |
| 2010 | 2595 | Metric tons | 9.03% |
| 2011 | 3660 | Metric tons | 41.04% |
| 2012 | 4328 | Metric tons | 18.25% |
