| 2007 | 2008 | 2009 | 2010 |
| January | |||
| February | February | February | February |
| March | March | March | March |
| April | April | April | April |
| May | May | May | May |
| June | June | June | June |
| July | July | July | July |
| August | August | August | August |
| September | September | September | September |
| October | October | October | October |
| November | November |
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| December | December | December | December |