| Year | Right Handed | Left Handed |
|---|---|---|
| 2007 | -22.78 | -21.45 |
| 2008 | -22.20 | -20.02 |
| 2009 | -20.04 | -20.33 |
| 2010 | -22.77 | -22.06 |
| 2011 | -22.25 | -22.02 |
| 2012 | -23.54 | -21.28 |
| 2013 | -22.08 | -21.42 |
| 2014 | -23.17 | -23.12 |
| 2015 | -21.61 | -21.07 |
| 2016 | -22.07 | -21.33 |
| 2017 | -20.76 | -21.85 |
| 2018 | -20.54 | -20.46 |
| 2019 | -21.33 | -22.09 |