| 时间 | 平均 | 最高 | 最低 |
|---|---|---|---|
| 2025 | 2.65 | 2.89 | 2.43 |
| 2024 | 2.4 | 3.43 | 1.86 |
| 2023 | 4.41 | 5.87 | 3.33 |
| 2022 | 6.12 | 7.73 | 5.26 |
| 2021 | 5.87 | 8.35 | 4.44 |
| 2020 | 4.57 | 7.75 | 2.76 |
| 2019 | 2.48 | 3.72 | 1.6 |
| 2018 | 2.63 | 4.3 | 1.62 |
| 2017 | 4.8 | 7.1 | 3.66 |
| 2016 | 6.01 | 7.13 | 4.91 |
| 2015 | 7.5 | 10.61 | 5.85 |
| 2014 | 6.65 | 8.4 | 5.39 |
| 2013 | 6.81 | 9.03 | 5.12 |
| 2012 | 7.28 | 10.72 | 5.71 |
| 2011 | 10.36 | 14.6 | 6.55 |
| 2010 | 11.53 | 16.02 | 8.58 |
| 2009 | 6.08 | 8.97 | 4.24 |
| 2008 | 4.75 | 7.72 | 2.96 |
| 2007 | 3.15 | 4.74 | 2.18 |
| 2006 | 3.06 | 5.03 | 1.97 |