Source: United States Geological Survey (USGS) Minerals Resources Program
Note: Check source table for details and footnotes
Year | Production | Unit of Measure | % Change |
2002 | 470000 | Metric tons, gross weight | NA |
2003 | 475000 | Metric tons, gross weight | 1.06% |
2004 | 475000 | Metric tons, gross weight | 0.00% |
2005 | 480000 | Metric tons, gross weight | 1.05% |
2006 | 475000 | Metric tons, gross weight | -1.04% |