| 时间 | 平均 | 最高 | 最低 |
|---|---|---|---|
| 2025 | 2.75 | 3.59 | 2.07 |
| 2024 | 2.08 | 2.56 | 1.49 |
| 2023 | 2.76 | 4.08 | 2.08 |
| 2022 | 3.53 | 4.75 | 2.7 |
| 2021 | 3.41 | 5.35 | 2.28 |
| 2020 | 2.17 | 2.72 | 1.78 |
| 2019 | 2.16 | 2.94 | 1.74 |
| 2018 | 2.3 | 3.59 | 1.64 |
| 2017 | 4.94 | 7.82 | 3.15 |
| 2016 | 7.55 | 9.59 | 5.83 |
| 2015 | 7.11 | 10.8 | 4.41 |
| 2014 | 3.58 | 4.76 | 2.88 |
| 2013 | 2.77 | 3.69 | 2.29 |
| 2012 | 2.55 | 3.12 | 2.21 |
| 2011 | 4.07 | 5.74 | 2.51 |
| 2010 | 6.1 | 9.29 | 4.64 |
| 2009 | 4.51 | 7.39 | 1.81 |
| 2008 | 2.98 | 6.32 | 1.2 |
| 2007 | 7.88 | 11.74 | 4.28 |
| 2006 | 3.35 | 6.28 | 1.68 |
| 2005 | 1.58 | 2.01 | 1.2 |
| 2004 | 2.52 | 4.76 | 1.43 |