Source: United States Geological Survey (USGS) Minerals Resources Program
Note: Check source table for details and footnotes
| Year | Production | Unit of Measure | % Change |
| 2003 | 30.4619998931885 | Thousand metric tons | NA |
| 2004 | 0.987999975681305 | Thousand metric tons | -96.76% |
| 2006 | 57.6920013427734 | Thousand metric tons | 5,739.27% |
| 2007 | 67.5479965209961 | Thousand metric tons | 17.08% |
| 2008 | 65.3430023193359 | Thousand metric tons | -3.26% |
| 2009 | 35.9329986572266 | Thousand metric tons | -45.01% |
| 2010 | 62.0979995727539 | Thousand metric tons | 72.82% |
| 2011 | 60 | Thousand metric tons | -3.38% |
| 2012 | 48.6640014648438 | Thousand metric tons | -18.89% |
| 2013 | 53.242000579834 | Thousand metric tons | 9.41% |
