| Year | Quarter | Months in Quarter | Index Rate |
| 2009 | I | January, February & March | 1.0% |
| 2008 | IV | October, November & December | 3.0% |
| 2008 | III | July, August & September | 7.0% |
| 2008 | II | April, May & June | 6.5% |
| 2008 | I | January, February & March | 6.0% |
| 2007 | IV | October, November & December | 6.0% |
| 2007 | III | July, August & September | 5.0% |
| 2007 | II | April, May & June | 5.0% |
| 2007 | I | January, February & March | 4.0% |
| 2006 | IV | October, November & December | 3.5% |
| 2006 | III | July, August & September | 4.5% |
| 2006 | II | April, May & June | 5.5% |
| 2006 | I | January, February & March | 6.5% |
| 2005 | IV | October, November & December | 6.5% |
| 2005 | III | July, August & September | 6.0% |
| 2005 | II | April, May & June | 4.5% |
| 2005 | I | January, February & March | 5.0% |
| 2004 | IV | October, November & December | 5.0% |
| 2004 | III | July, August & September | 3.5% |
| 2004 | II | April, May & June | 3.0% |
| 2004 | I | January, February & March | 1.5% |
| 2003 | IV | October, November & December | 2.0% |
| 2003 | III | July, August & September | 2.0% |
| 2003 | II | April, May & June | 2.0% |
| 2003 | I | January, February & March | 3.5% |
| 2002 | IV | October, November & December | 2.0% |
| 2002 | III | July, August & September | 1.5% |
| 2002 | II | April, May & June | 1.0% |