| 时间 | 平均 | 最高 | 最低 |
|---|---|---|---|
| 2024 | 0 | ||
| 2023 | 2.67 | 2.77 | 2.56 |
| 2022 | 2.94 | 4.54 | 2.16 |
| 2021 | 3.5 | 4.59 | 2.64 |
| 2020 | 2.9 | 4.13 | 1.86 |
| 2019 | 2.17 | 2.64 | 1.85 |
| 2018 | 2.76 | 3.37 | 2.09 |
| 2017 | 3.07 | 4.03 | 2.63 |
| 2016 | 3.1 | 4.03 | 2.22 |
| 2015 | 3.02 | 4.55 | 1.98 |
| 2014 | 1.63 | 2.57 | 0.98 |
| 2013 | 6.46 | 21.82 | 0.85 |
| 2012 | 5.95 | 14.23 | 4.44 |
| 2011 | 8.1 | 11.04 | 5.37 |
| 2010 | 6.01 | 12.95 | 3.44 |
| 2009 | 3.84 | 4.94 | 2.07 |
| 2008 | 3.63 | 6.82 | 1.36 |
| 2007 | 5.55 | 9.44 | 2.41 |
| 2006 | 2.8 | 4.01 | 2.25 |
| 2005 | 3.09 | 4.61 | 2.04 |