| 时间 | 平均 | 最高 | 最低 |
|---|---|---|---|
| 2025 | 1.5 | 2.3 | 0.93 |
| 2024 | 1.03 | 1.58 | 0.76 |
| 2023 | 1.66 | 2.1 | 1.39 |
| 2022 | 2.45 | 3.99 | 1.59 |
| 2021 | 3.04 | 3.83 | 2.25 |
| 2020 | 2.56 | 4.45 | 1.75 |
| 2019 | 2.04 | 2.57 | 1.56 |
| 2018 | 2.5 | 3.77 | 1.6 |
| 2017 | 4.96 | 6.74 | 3.12 |
| 2016 | 8.75 | 12.11 | 6.56 |
| 2015 | 6.11 | 11.39 | 3.93 |
| 2014 | 4.56 | 8.45 | 2.85 |
| 2013 | 2.59 | 3.35 | 2.04 |
| 2012 | 2.49 | 3.14 | 1.95 |
| 2011 | 3.58 | 5.35 | 2.38 |
| 2010 | 4.93 | 7.71 | 3.59 |
| 2009 | 4.41 | 7.61 | 1.93 |
| 2008 | 2.47 | 4.62 | 1.11 |