|
Month
|
2011
|
2010
|
2009
|
| January | 1.46 | 1.46 | |
| February | 1.46 | 1.46 | |
| March | 1.46 | 1.46 | |
| April | 1.46 | 1.46 | |
| May | 1.57 | 1.46 | |
| June | 1.46 | ||
| July | 1.46 | 1.30 | |
| August | 1.57 | 1.46 | 1.42 |
| September | 1.46 | 1.42 | |
| October | 1.46 | 1.42 | |
| November | 1.46 | 1.46 | |
| December | 1.46 | 1.46 |