Source: United States Geological Survey (USGS) Minerals Resources Program
Note: Check source table for details and footnotes
| Year | Production | Unit of Measure | % Change |
| 2002 | 73 | Thousand metric tons | NA |
| 2003 | 33 | Thousand metric tons | -54.79% |
| 2004 | 59.2309989929199 | Thousand metric tons | 79.49% |
| 2005 | 63.3769989013672 | Thousand metric tons | 7.00% |
| 2006 | 32.7980003356934 | Thousand metric tons | -48.25% |
| 2007 | 2.73000001907349 | Thousand metric tons | -91.68% |
| 2008 | 2.79999995231628 | Thousand metric tons | 2.56% |
| 2009 | 8.10499954223633 | Thousand metric tons | 189.46% |
| 2010 | 26.9179992675781 | Thousand metric tons | 232.12% |
| 2011 | 9.28800010681152 | Thousand metric tons | -65.50% |
| 2012 | 91.6100006103516 | Thousand metric tons | 886.33% |
| 2013 | 280.476013183594 | Thousand metric tons | 206.16% |
