| 时间 | 平均 | 最高 | 最低 |
|---|---|---|---|
| 2025 | 1.36 | 1.53 | 1.2 |
| 2024 | 1.35 | 1.72 | 1.05 |
| 2023 | 1.8 | 2.25 | 1.44 |
| 2022 | 1.48 | 1.97 | 1.1 |
| 2021 | 2.04 | 2.71 | 1.53 |
| 2020 | 1.73 | 2.71 | 0.83 |
| 2019 | 0.78 | 1 | 0.66 |
| 2018 | 1.15 | 1.75 | 0.72 |
| 2017 | 1.92 | 2.29 | 1.66 |
| 2016 | 2.23 | 2.97 | 1.88 |
| 2015 | 2.89 | 4.41 | 2.04 |
| 2014 | 2.29 | 2.63 | 1.94 |
| 2013 | 2.49 | 3.04 | 2.11 |
| 2012 | 2.61 | 3.08 | 2.18 |
| 2011 | 4.5 | 6.73 | 3 |
| 2010 | 5.76 | 7.58 | 4.6 |
| 2009 | 3.43 | 6.02 | 1.82 |
| 2008 | 2.84 | 5.65 | 1.21 |
| 2007 | 4.15 | 6.17 | 1.68 |
| 2006 | 1.29 | 1.8 | 0.86 |
| 2005 | 1.04 | 1.48 | 0.79 |
| 2004 | 1.31 | 2.35 | 0.86 |