| 时间 | 平均 | 最高 | 最低 |
|---|---|---|---|
| 2026 | 0.52 | 0.56 | 0.47 |
| 2025 | 0.46 | 0.56 | 0.37 |
| 2024 | 0.32 | 0.53 | 0.25 |
| 2023 | 0.35 | 0.44 | 0.29 |
| 2022 | 0.42 | 0.51 | 0.35 |
| 2021 | 0.66 | 0.96 | 0.46 |
| 2020 | 0.6 | 0.74 | 0.49 |
| 2019 | 0.78 | 0.94 | 0.67 |
| 2018 | 1.26 | 2.61 | 0.72 |
| 2017 | 1.87 | 2.53 | 1.07 |
| 2016 | 1.59 | 2.1 | 1.15 |
| 2015 | 1.56 | 2.92 | 1.01 |
| 2014 | 0.76 | 1.32 | 0.55 |
| 2013 | 0.3 | 0.6 | 0.22 |
| 2012 | 0.23 | 0.37 | 0.18 |
| 2011 | 0.35 | 0.56 | 0.2 |
| 2010 | 0.69 | 0.97 | 0.47 |
| 2009 | 0.68 | 1 | 0.4 |
| 2008 | 0.58 | 1.17 | 0.3 |