Source: United States Geological Survey (USGS) Minerals Resources Program
Note: Check source table for details and footnotes
Year | Production | Unit of Measure | % Change |
2002 | 66300 | Metric tons, gross weight | NA |
2003 | 91000 | Metric tons, gross weight | 37.25% |
2004 | 194909 | Metric tons, gross weight | 114.19% |
2005 | 78915 | Metric tons, gross weight | -59.51% |
2006 | 73037 | Metric tons, gross weight | -7.45% |
2007 | 103830 | Metric tons, gross weight | 42.16% |
2008 | 55880 | Metric tons, gross weight | -46.18% |
2009 | 37105 | Metric tons, gross weight | -33.60% |
2010 | 40000 | Metric tons, gross weight | 7.80% |
2011 | 40000 | Metric tons, gross weight | 0.00% |
2012 | 40000 | Metric tons, gross weight | 0.00% |