Source: United States Geological Survey (USGS) Minerals Resources Program
Note: Check source table for details and footnotes
| Year | Production | Unit of Measure | % Change |
| 2003 | 2025 | Thousand metric tons | NA |
| 2004 | 1500 | Thousand metric tons | -25.93 % |
| 2005 | 1791 | Thousand metric tons | 19.40 % |
| 2006 | 1942 | Thousand metric tons | 8.43 % |
| 2007 | 2000 | Thousand metric tons | 2.99 % |
| 2008 | 2000 | Thousand metric tons | 0.00 % |
| 2009 | 1600 | Thousand metric tons | -20.00 % |
| 2010 | 2000 | Thousand metric tons | 25.00 % |
| 2011 | 2000 | Thousand metric tons | 0.00 % |
| 2012 | 2000 | Thousand metric tons | 0.00 % |
| 2013 | 2000 | Thousand metric tons | 0.00 % |
