Source: United States Geological Survey (USGS) Minerals Resources Program
Note: Check source table for details and footnotes
| Year | Production | Unit of Measure | % Change |
| 2002 | 84236.3984375 | Thousand metric tons | NA |
| 2003 | 91759.796875 | Thousand metric tons | 8.93% |
| 2004 | 96980 | Thousand metric tons | 5.69% |
| 2005 | 96764.3984375 | Thousand metric tons | -0.22% |
| 2006 | 102000 | Thousand metric tons | 5.41% |
| 2007 | 105000 | Thousand metric tons | 2.94% |
| 2008 | 99900 | Thousand metric tons | -4.86% |
| 2009 | 92000 | Thousand metric tons | -7.91% |
| 2010 | 95900 | Thousand metric tons | 4.24% |
| 2011 | 104000 | Thousand metric tons | 8.45% |
| 2012 | 105000 | Thousand metric tons | 0.96% |
