| 时间 | 平均 | 最高 | 最低 |
|---|---|---|---|
| 2025 | 2.01 | 2.88 | 1.61 |
| 2024 | 1.56 | 2.05 | 1.13 |
| 2023 | 1.76 | 2.02 | 1.51 |
| 2022 | 2.2 | 3.69 | 1.57 |
| 2021 | 3.47 | 4.8 | 2.7 |
| 2020 | 4.16 | 5.21 | 3.14 |
| 2019 | 3.53 | 4.59 | 2.43 |
| 2018 | 4.34 | 5.79 | 2.82 |
| 2017 | 4.72 | 5.82 | 3.62 |
| 2016 | 4.04 | 4.51 | 3.48 |
| 2015 | 4.53 | 7.25 | 3.17 |
| 2014 | 3.85 | 4.76 | 3.04 |
| 2013 | 2.83 | 3.61 | 2.04 |
| 2012 | 2.07 | 2.56 | 1.67 |
| 2011 | 3.88 | 6.25 | 1.78 |
| 2010 | 4.28 | 5.76 | 3.22 |
| 2009 | 3.52 | 4.72 | 2.36 |
| 2008 | 4.76 | 9 | 1.83 |
| 2007 | 8.75 | 13.19 | 6.45 |
| 2006 | 5.01 | 7.02 | 3.46 |
| 2005 | 3.86 | 5.62 | 2.53 |