| 时间 | 平均 | 最高 | 最低 |
|---|---|---|---|
| 2025 | 2.53 | 2.89 | 2.22 |
| 2024 | 3.1 | 4.13 | 2.05 |
| 2023 | 3.05 | 4.66 | 2.07 |
| 2022 | 1.87 | 2.75 | 1.11 |
| 2021 | 1.83 | 2.28 | 1.3 |
| 2020 | 2.15 | 2.99 | 1.85 |
| 2019 | 2.72 | 3.4 | 2.12 |
| 2018 | 3.92 | 5.1 | 2.8 |
| 2017 | 4.35 | 5.61 | 3.42 |
| 2016 | 6.25 | 8.12 | 5.4 |
| 2015 | 7.93 | 13.5 | 3.39 |
| 2014 | 7.59 | 13.4 | 4.25 |
| 2013 | 3.14 | 5.87 | 1.84 |
| 2012 | 2.07 | 2.56 | 1.61 |
| 2011 | 2.92 | 3.77 | 1.98 |
| 2010 | 3.74 | 5.06 | 3 |
| 2009 | 2.65 | 4.08 | 1.24 |
| 2008 | 2.33 | 4.48 | 1.07 |
| 2007 | 3.27 | 4.89 | 2.3 |
| 2006 | 2.37 | 2.85 | 1.8 |
| 2005 | 2.15 | 3.29 | 1.31 |
| 2004 | 2.04 | 3.7 | 1.28 |