| Month | Change |
|---|---|
| 5/10 | -23.20 |
| 6/10 | -27.70 |
| 7/10 | -31.59 |
| 9/10 | -26.43 |
| 10/10 | -28.22 |
| Month | Change | 4/11 | -26.96 |
| 5/11 | -26.07 |
| 7/11 | -22.30 |
| 8/11 | -23.86 |
| Month | Change | 7/12 | -21.98 |
| 8/12 | -22.49 |
| 9/12 | -22.19 |
| 10/12 | -19.76 |
| Month | Change | 4/13 | -20.94 |
| 5/13 | -20.44 |
| 6/13 | -21.34 |
| 7/13 | -22.69 |
| 8/13 | -21.80 |
| 9/13 | -21.47 |
| Month | Change | 3/14 | -20.42 |
| 4/14 | -21.59 |
| 5/14 | -23.16 |
| 6/14 | -23.18 |
| 7/14 | -23.45 |
| 8/14 | -21.75 |
| 9/14 | -21.81 |
| 10/14 | -22.34 |
| Month | Change | 4/15 | -21.51 |
| 5/15 | -23.53 |
| 6/15 | -23.85 |
| 7/15 | -25.20 |