| 时间 | 平均 | 最高 | 最低 |
|---|---|---|---|
| 2025 | 0.69 | 0.72 | 0.65 |
| 2024 | 0.7 | 0.84 | 0.59 |
| 2023 | 0.81 | 0.96 | 0.57 |
| 2022 | 0.99 | 1.27 | 0.76 |
| 2021 | 0.85 | 1 | 0.76 |
| 2020 | 0.98 | 1.24 | 0.86 |
| 2019 | 1.35 | 1.98 | 0.96 |
| 2018 | 3.43 | 7.55 | 1.6 |
| 2017 | 3.27 | 7.16 | 1.81 |
| 2016 | 3.26 | 4.71 | 2.56 |
| 2015 | 4.35 | 8.3 | 2.15 |
| 2014 | 1.68 | 2.35 | 1.28 |
| 2013 | 2.23 | 4.7 | 1.36 |
| 2012 | 2.15 | 2.71 | 1.65 |
| 2011 | 3.34 | 4.65 | 1.78 |
| 2010 | 3.67 | 4.91 | 2.86 |
| 2009 | 3.61 | 5.13 | 1.74 |
| 2008 | 3.03 | 7.18 | 1.1 |
| 2007 | 6.36 | 7.93 | 4.85 |