| 时间 | 平均 | 最高 | 最低 |
|---|---|---|---|
| 2025 | 1.79 | 2.82 | 0.69 |
| 2024 | 2.99 | 4.54 | 2.43 |
| 2023 | 2.88 | 3.96 | 2.19 |
| 2022 | 2.98 | 4.07 | 2.12 |
| 2021 | 2.4 | 3.57 | 1.51 |
| 2020 | 2.3 | 4.64 | 1.67 |
| 2019 | 2.45 | 3.25 | 1.89 |
| 2018 | 2.32 | 3.17 | 1.67 |
| 2017 | 2.64 | 3.72 | 2 |
| 2016 | 4.75 | 6.59 | 3.44 |
| 2015 | 4.64 | 8.18 | 2.46 |
| 2014 | 1.94 | 2.81 | 1.45 |
| 2013 | 2.02 | 3.29 | 1.18 |
| 2012 | 1.4 | 1.86 | 0.99 |
| 2011 | 1.91 | 3 | 1.21 |
| 2010 | 1.45 | 1.97 | 1.11 |
| 2009 | 1.1 | 1.71 | 0.58 |
| 2008 | 1.03 | 1.88 | 0.44 |
| 2007 | 1.94 | 3.17 | 1.1 |
| 2006 | 2.13 | 3.16 | 1.01 |
| 2005 | 3.23 | 3.87 | 2.02 |
| 2004 | 2.8 | 4.27 | 1.95 |