| 时间 | 平均 | 最高 | 最低 |
|---|---|---|---|
| 2025 | 1.04 | 1.28 | 0.93 |
| 2024 | 1.04 | 1.41 | 0.8 |
| 2023 | 1.66 | 2.3 | 1.33 |
| 2022 | 1.73 | 3.3 | 0.7 |
| 2021 | 0.69 | 1.14 | 0.57 |
| 2020 | 0.7 | 0.82 | 0.6 |
| 2019 | 0.69 | 0.96 | 0.58 |
| 2018 | 1.02 | 1.71 | 0.64 |
| 2017 | 2.39 | 3.05 | 1.64 |
| 2016 | 2.23 | 2.6 | 1.66 |
| 2015 | 2.08 | 3.35 | 1.28 |
| 2014 | 1.46 | 2.21 | 1.12 |
| 2013 | 1.1 | 1.37 | 0.92 |
| 2012 | 1.24 | 1.64 | 0.88 |
| 2011 | 2.63 | 4.17 | 1.16 |
| 2010 | 3.48 | 5.03 | 2.65 |
| 2009 | 2.15 | 3.98 | 1.11 |
| 2008 | 1.98 | 4.25 | 0.71 |
| 2007 | 3.5 | 4.21 | 2.99 |