| 时间 | 平均 | 最高 | 最低 |
|---|---|---|---|
| 2025 | 3.71 | 4.4 | 3.05 |
| 2024 | 3.26 | 6.04 | 2.37 |
| 2023 | 4 | 5.01 | 3.02 |
| 2022 | 2.66 | 4.54 | 2.14 |
| 2021 | 2.01 | 2.43 | 1.22 |
| 2020 | 1.2 | 1.9 | 0.76 |
| 2019 | 0.98 | 1.23 | 0.64 |
| 2018 | 0.82 | 1.12 | 0.59 |
| 2017 | 1.39 | 1.93 | 1.04 |
| 2016 | 1.5 | 2.53 | 0.88 |
| 2015 | 1.04 | 1.42 | 0.72 |
| 2014 | 0.93 | 1.08 | 0.7 |
| 2013 | 0.79 | 1.12 | 0.49 |
| 2012 | 0.54 | 0.73 | 0.41 |
| 2011 | 1.16 | 1.8 | 0.57 |
| 2010 | 1.51 | 1.98 | 1.19 |
| 2009 | 1.05 | 1.27 | 0.84 |
| 2008 | 1.15 | 2.21 | 0.67 |
| 2007 | 1.72 | 2.3 | 1 |
| 2006 | 1.01 | 1.51 | 0.69 |
| 2005 | 0.59 | 0.73 | 0.39 |
| 2004 | 0.64 | 1.12 | 0.43 |