| 时间 | 平均 | 最高 | 最低 |
|---|---|---|---|
| 2025 | 2.59 | 3.02 | 2.27 |
| 2024 | 2.3 | 2.84 | 1.91 |
| 2023 | 3.03 | 3.5 | 2.57 |
| 2022 | 2.73 | 3.76 | 1.92 |
| 2021 | 2.52 | 3.5 | 1.88 |
| 2020 | 2.7 | 3.56 | 2.04 |
| 2019 | 2.7 | 3.61 | 2.13 |
| 2018 | 2.8 | 4.02 | 1.95 |
| 2017 | 5.28 | 6.8 | 3.85 |
| 2016 | 7.2 | 8.69 | 5.3 |
| 2015 | 5.12 | 8.72 | 2.69 |
| 2014 | 2.11 | 3.58 | 1.73 |
| 2013 | 1.82 | 2.48 | 1.19 |
| 2012 | 1.57 | 1.98 | 1.23 |
| 2011 | 2.73 | 4.26 | 1.4 |
| 2010 | 3.12 | 4.23 | 2.44 |
| 2009 | 2.36 | 3.14 | 1.36 |
| 2008 | 2.18 | 2.7 | 0.94 |
| 2007 | 2.65 | 4.69 | 1.21 |
| 2006 | 1.46 | 2.05 | 1.1 |
| 2005 | 1.39 | 1.76 | 0.87 |
| 2004 | 2.89 | 5.9 | 1.39 |