Source: United States Geological Survey (USGS) Minerals Resources Program
Note: Check source table for details and footnotes
| Year | Production | Unit of Measure | % Change |
| 2003 | 82091.7421875 | Thousand metric tons | NA |
| 2004 | 82974.4921875 | Thousand metric tons | 1.08 % |
| 2005 | 83058.1328125 | Thousand metric tons | 0.10 % |
| 2006 | 84270.3984375 | Thousand metric tons | 1.46 % |
| 2007 | 86771 | Thousand metric tons | 2.97 % |
| 2008 | 86171 | Thousand metric tons | -0.69 % |
| 2009 | 86000 | Thousand metric tons | -0.20 % |
