| 时间 | 平均 | 最高 | 最低 |
|---|---|---|---|
| 2025 | 1.78 | 1.85 | 1.73 |
| 2024 | 1.86 | 2.19 | 1.59 |
| 2023 | 2.18 | 3.07 | 1.79 |
| 2022 | 1.89 | 2.25 | 1.61 |
| 2021 | 1.95 | 2.25 | 1.77 |
| 2020 | 2.25 | 2.75 | 1.99 |
| 2019 | 2.81 | 4.36 | 2.23 |
| 2018 | 3.04 | 3.67 | 2.29 |
| 2017 | 3.13 | 3.76 | 2.72 |
| 2016 | 3.1 | 4.32 | 2.63 |
| 2015 | 5.51 | 8.33 | 3.65 |
| 2014 | 3.92 | 4.44 | 3.5 |
| 2013 | 3.63 | 4.16 | 2.97 |
| 2012 | 2.9 | 3.39 | 2.34 |
| 2011 | 4.22 | 5.65 | 2.36 |
| 2010 | 3.35 | 4.51 | 2.61 |
| 2009 | 2.57 | 3.71 | 1.58 |
| 2008 | 2.21 | 4.14 | 1.13 |
| 2007 | 3.04 | 4.79 | 1.45 |
| 2006 | 1.21 | 1.47 | 0.91 |
| 2005 | 1.23 | 1.47 | 0.98 |