| 时间 | 平均 | 最高 | 最低 |
|---|---|---|---|
| 2025 | 2.78 | 3.04 | 2.42 |
| 2024 | 2.28 | 3.61 | 1.69 |
| 2023 | 2.85 | 3.37 | 2.55 |
| 2022 | 2.73 | 3.71 | 1.96 |
| 2021 | 2.43 | 2.95 | 1.9 |
| 2020 | 3.27 | 4.84 | 2.29 |
| 2019 | 3.57 | 4.51 | 2.46 |
| 2018 | 3.47 | 5.1 | 2.64 |
| 2017 | 4.81 | 6.36 | 3.47 |
| 2016 | 6.54 | 10.24 | 5.21 |
| 2015 | 8.58 | 16.22 | 4.07 |
| 2014 | 4.02 | 4.81 | 3.25 |
| 2013 | 4.42 | 5.54 | 3.25 |
| 2012 | 4.45 | 5.76 | 2.65 |
| 2011 | 11.19 | 18.71 | 4.45 |
| 2010 | 12.91 | 19.46 | 8.52 |
| 2009 | 10.25 | 14.98 | 5.72 |
| 2008 | 8.44 | 12.28 | 3.69 |
| 2007 | 14.49 | 26.22 | 4.27 |