| 时间 | 平均 | 最高 | 最低 |
|---|---|---|---|
| 2025 | 0 | ||
| 2024 | 0 | ||
| 2023 | 2.83 | 2.93 | 2.71 |
| 2022 | 3.21 | 5.15 | 2.32 |
| 2021 | 3.68 | 5.21 | 2.79 |
| 2020 | 3.36 | 4.91 | 2.31 |
| 2019 | 2.74 | 3.33 | 2.37 |
| 2018 | 3.23 | 3.76 | 2.57 |
| 2017 | 3.57 | 4.39 | 3.23 |
| 2016 | 3.68 | 4.67 | 2.61 |
| 2015 | 4.79 | 7.36 | 3.03 |
| 2014 | 2.9 | 4.2 | 2.22 |
| 2013 | 7.82 | 23.36 | 2.13 |
| 2012 | 6.79 | 15.23 | 4.75 |
| 2011 | 9.62 | 13.35 | 6.41 |
| 2010 | 6.72 | 15.65 | 3.88 |
| 2009 | 3.38 | 4.6 | 1.74 |
| 2008 | 2.7 | 4.5 | 1.14 |
| 2007 | 5.28 | 9.68 | 2.26 |
| 2006 | 2.23 | 3.1 | 1.55 |
| 2005 | 1.8 | 2.33 | 1.37 |