| 时间 | 平均 | 最高 | 最低 |
|---|---|---|---|
| 2025 | 2.71 | 3.03 | 2.41 |
| 2024 | 2.63 | 3.54 | 2.02 |
| 2023 | 3.93 | 5.22 | 3.01 |
| 2022 | 4.15 | 5.99 | 2.66 |
| 2021 | 4.63 | 6.74 | 3.39 |
| 2020 | 4.82 | 6.76 | 3.85 |
| 2019 | 3.26 | 5.57 | 2.15 |
| 2018 | 3.03 | 4.59 | 1.91 |
| 2017 | 4.11 | 5.05 | 3.36 |
| 2016 | 5.15 | 6.62 | 3.41 |
| 2015 | 5.33 | 9.21 | 3.68 |
| 2014 | 4.23 | 5.03 | 3.28 |
| 2013 | 3.16 | 4.26 | 2.23 |
| 2012 | 3.9 | 8.25 | 2.14 |
| 2011 | 9.51 | 12.04 | 6.27 |
| 2010 | 6.11 | 9.81 | 4.31 |
| 2009 | 3.88 | 4.98 | 2.41 |
| 2008 | 3.71 | 7.45 | 1.49 |
| 2007 | 4.35 | 6.28 | 3.34 |