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 | 66943 | Thousand metric tons | -22.31% |
| 2010 | 82283 | Thousand metric tons | 22.92% |
| 2011 | 81028 | Thousand metric tons | -1.53% |
| 2012 | 81405 | Thousand metric tons | 0.47% |
