| 时间 | 平均 | 最高 | 最低 |
|---|---|---|---|
| 2025 | 0.66 | 0.79 | 0.59 |
| 2024 | 0.6 | 0.78 | 0.43 |
| 2023 | 0.92 | 1.31 | 0.63 |
| 2022 | 1.35 | 1.7 | 0.97 |
| 2021 | 1.43 | 2.67 | 0.81 |
| 2020 | 2.42 | 3.93 | 1.67 |
| 2019 | 3.5 | 6.47 | 2.14 |
| 2018 | 1.95 | 2.79 | 1.35 |
| 2017 | 2.88 | 4.01 | 2.25 |
| 2016 | 3.3 | 4.4 | 2.61 |
| 2015 | 1.75 | 3.87 | 0.76 |
| 2014 | 0.92 | 1.18 | 0.72 |
| 2013 | 0.71 | 0.86 | 0.56 |
| 2012 | 0.83 | 1.02 | 0.73 |
| 2011 | 1.65 | 2.79 | 0.92 |
| 2010 | 2.15 | 2.62 | 1.63 |
| 2009 | 1.67 | 2.33 | 1.26 |
| 2008 | 1.8 | 3.01 | 0.92 |