| 时间 | 平均 | 最高 | 最低 |
|---|---|---|---|
| 2025 | 1.77 | 1.84 | 1.64 |
| 2024 | 1.53 | 1.95 | 1.19 |
| 2023 | 1.29 | 1.43 | 1.12 |
| 2022 | 1.22 | 1.45 | 1.06 |
| 2021 | 1.46 | 1.72 | 1.29 |
| 2020 | 1.75 | 2.07 | 1.56 |
| 2019 | 2.23 | 2.59 | 1.98 |
| 2018 | 2.38 | 2.77 | 2.03 |
| 2017 | 2.67 | 3.03 | 2.21 |
| 2016 | 2.08 | 2.58 | 1.81 |
| 2015 | 3.13 | 5.11 | 2.33 |
| 2014 | 1.91 | 3.15 | 1.61 |
| 2013 | 2.03 | 2.41 | 1.75 |
| 2012 | 2.13 | 2.37 | 1.9 |
| 2011 | 2.79 | 3.6 | 2.11 |
| 2010 | 4.54 | 6.53 | 3.4 |
| 2009 | 4.47 | 6.07 | 3.53 |
| 2008 | 5.68 | 10.25 | 3.46 |
| 2007 | 8.29 | 10.25 | 6.58 |
| 2006 | 5.73 | 7.15 | 3.53 |
| 2005 | 5.91 | 7.23 | 3.86 |
| 2004 | 5.12 | 6.66 | 3.14 |