Source: United States Geological Survey (USGS) Minerals Resources Program
Note: Check source table for details and footnotes
| Year | Production | Unit of Measure | % Change |
| 2003 | 62710 | Thousand metric tons | NA |
| 2004 | 65645.6015625 | Thousand metric tons | 4.68% |
| 2005 | 66186.203125 | Thousand metric tons | 0.82% |
| 2006 | 70816 | Thousand metric tons | 7.00% |
| 2007 | 72389 | Thousand metric tons | 2.22% |
