| 时间 | 平均 | 最高 | 最低 |
|---|---|---|---|
| 2025 | 3.2 | 3.91 | 2.8 |
| 2024 | 2.86 | 5.59 | 1.73 |
| 2023 | 2.5 | 2.93 | 2.08 |
| 2022 | 2.34 | 2.95 | 1.76 |
| 2021 | 2.09 | 2.9 | 1.71 |
| 2020 | 2.6 | 4.82 | 1.69 |
| 2019 | 2.08 | 2.94 | 1.59 |
| 2018 | 1.93 | 2.68 | 1.38 |
| 2017 | 3.34 | 4.73 | 2.28 |
| 2016 | 2.57 | 3.5 | 2.2 |
| 2015 | 3.89 | 6.96 | 2.4 |
| 2014 | 1.68 | 2.42 | 1.22 |
| 2013 | 2.61 | 3.58 | 1.71 |
| 2012 | 2.71 | 3.32 | 2.07 |
| 2011 | 3.34 | 4.75 | 2.02 |
| 2010 | 5.02 | 6.9 | 3.38 |
| 2009 | 7.59 | 10.44 | 5.67 |
| 2008 | 9.97 | 15.63 | 3.53 |
| 2007 | 8.19 | 17.54 | 2.12 |
| 2006 | 2.62 | 3.94 | 1.84 |
| 2005 | 2.16 | 3.2 | 1.13 |
| 2004 | 1.92 | 3.3 | 1.21 |