Source: United States Geological Survey (USGS) Minerals Resources Program
Note: Check source table for details and footnotes
| Year | Production | Unit of Measure | % Change |
| 2003 | 594.35498046875 | Thousand metric tons of K | NA |
| 2004 | 590 | Thousand metric tons of K | -0.73 % |
| 2005 | 575 | Thousand metric tons of K | -2.54 % |
| 2006 | 435.191009521484 | Thousand metric tons of K | -24.31 % |
| 2007 | 435 | Thousand metric tons of K | -0.04 % |
| 2008 | 435 | Thousand metric tons of K | 0.00 % |
