Source: United States Geological Survey (USGS) Minerals Resources Program
Note: Check source table for details and footnotes
| Year | Production | Unit of Measure | % Change |
| 2003 | 468000 | Metric tons | NA |
| 2004 | 532000 | Metric tons | 13.68% |
| 2005 | 489000 | Metric tons | -8.08% |
| 2006 | 589000 | Metric tons | 20.45% |
| 2007 | 455000 | Metric tons | -22.75% |
| 2008 | 648000 | Metric tons | 42.42% |
| 2009 | 396000 | Metric tons | -38.89% |
| 2010 | 662000 | Metric tons | 67.17% |
| 2011 | 710000 | Metric tons | 7.25% |
| 2012 | 666000 | Metric tons | -6.20% |
