| 时间 | 平均 | 最高 | 最低 |
|---|---|---|---|
| 2025 | 1.86 | 2.04 | 1.48 |
| 2024 | 2.06 | 2.48 | 1.68 |
| 2023 | 2.04 | 2.42 | 1.64 |
| 2022 | 1.65 | 1.91 | 1.47 |
| 2021 | 1.6 | 1.83 | 1.42 |
| 2020 | 1.97 | 2.28 | 1.69 |
| 2019 | 1.94 | 2.45 | 1.66 |
| 2018 | 2.47 | 4.29 | 1.6 |
| 2017 | 6.39 | 8.44 | 3.99 |
| 2016 | 6.32 | 8.01 | 5.86 |
| 2015 | 7.03 | 12.24 | 4.83 |
| 2014 | 3.2 | 5.18 | 2.6 |
| 2013 | 3.18 | 3.69 | 2.79 |
| 2012 | 3.08 | 3.57 | 2.58 |
| 2011 | 4.55 | 5.85 | 3.22 |
| 2010 | 7.08 | 10.01 | 5.31 |
| 2009 | 6.43 | 7.55 | 5.09 |
| 2008 | 7.26 | 12.19 | 4.49 |
| 2007 | 10.36 | 13.74 | 7 |
| 2006 | 7.71 | 9.99 | 6.11 |
| 2005 | 6.48 | 8.76 | 5.35 |