| 时间 | 平均 | 最高 | 最低 |
|---|---|---|---|
| 2025 | 1.95 | 2.48 | 1.67 |
| 2024 | 1.25 | 3.11 | 0.93 |
| 2023 | 1.28 | 1.99 | 1.05 |
| 2022 | 0.96 | 1.18 | 0.7 |
| 2021 | 0.84 | 1.12 | 0.74 |
| 2020 | 1.34 | 2.15 | 0.92 |
| 2019 | 1.23 | 1.57 | 0.9 |
| 2018 | 1.56 | 2.39 | 0.91 |
| 2017 | 3.81 | 5.3 | 2.39 |
| 2016 | 5.57 | 8.41 | 4.32 |
| 2015 | 6.28 | 14.91 | 2.82 |
| 2014 | 2.32 | 3.39 | 1.47 |
| 2013 | 1.35 | 1.76 | 1.12 |
| 2012 | 1.2 | 1.38 | 1.1 |
| 2011 | 1.57 | 1.88 | 1.18 |
| 2010 | 2.11 | 2.91 | 1.61 |
| 2009 | 1.99 | 2.77 | 1.2 |
| 2008 | 2.5 | 5.43 | 0.82 |
| 2007 | 3.44 | 4.61 | 2.12 |
| 2006 | 1.78 | 1.78 | 1.78 |