Source: United States Geological Survey (USGS) Minerals Resources Program
Note: Check source table for details and footnotes
| Year | Production | Unit of Measure | % Change |
| 2002 | 29 | Metric tons | NA |
| 2003 | 31 | Metric tons | 6.90% |
| 2004 | 37 | Metric tons | 19.35% |
| 2005 | 49.2000007629395 | Metric tons | 32.97% |
| 2006 | 50 | Metric tons | 1.63% |
| 2007 | 50 | Metric tons | 0.00% |
| 2008 | 69.9059982299805 | Metric tons | 39.81% |
| 2009 | 70.0619964599609 | Metric tons | 0.22% |
| 2010 | 64.5960006713867 | Metric tons | -7.80% |
| 2011 | 73.0810012817383 | Metric tons | 13.14% |
| 2012 | 128.199996948242 | Metric tons | 75.42% |
