| 时间 | 平均 | 最高 | 最低 |
|---|---|---|---|
| 2025 | 0.47 | 0.53 | 0.39 |
| 2024 | 0.36 | 0.53 | 0.26 |
| 2023 | 0.63 | 0.92 | 0.33 |
| 2022 | 0.7 | 1.07 | 0.36 |
| 2021 | 0.43 | 0.55 | 0.3 |
| 2020 | 0.6 | 0.81 | 0.48 |
| 2019 | 0.69 | 0.9 | 0.59 |
| 2018 | 1.18 | 2.3 | 0.57 |
| 2017 | 1.4 | 2.06 | 1.11 |
| 2016 | 1.47 | 1.89 | 1.15 |
| 2015 | 1.62 | 2.94 | 0.82 |
| 2014 | 0.81 | 1.02 | 0.59 |
| 2013 | 1.74 | 3.4 | 0.87 |
| 2012 | 2.92 | 4.16 | 1.62 |
| 2011 | 2.77 | 5.95 | 1.47 |
| 2010 | 5.72 | 10.31 | 3.4 |
| 2009 | 10.97 | 18.29 | 5.88 |