| Month | Effective Rate |
| May 2013 | 4.14% |
| Apr 2013 | 4.15% |
| Mar 2013 | 4.29% |
| Feb 2013 | 4.28% |
| Jan 2013 | 4.20% |
| Dec 2012 | 4.00% |
| Nov 2012 | 4.16% |
| Oct 2012 | 4.25% |
| Sep 2012 | 4.27% |
| Aug 2012 | 4.44% |
| Jul 2012 | 4.45% |
| Jun 2012 | 4.49% |
| May 2012 | 4.45% |
| Apr 2012 | 4.74% |
| Mar 2012 | 4.58% |
| Feb 2012 | 4.7% |
| Jan 2012 | 4.83% |
| Dec 2011 | 4.94% |
| Nov 2011 | 4.94% |
| Oct 2011 | 4.83% |
| Sep 2011 | 4.69% |
| Aug 2011 | 5.13% |
| Jul 2011 | 5.58% |
| Jun 2011 | 5.51% |