| 时间 | 平均 | 最高 | 最低 |
|---|---|---|---|
| 2025 | 1.71 | 1.85 | 1.48 |
| 2024 | 1.67 | 2.15 | 1.35 |
| 2023 | 1.86 | 2.31 | 1.5 |
| 2022 | 2.33 | 3.14 | 1.63 |
| 2021 | 2.41 | 3.32 | 1.76 |
| 2020 | 1.74 | 2.67 | 1.26 |
| 2019 | 1.31 | 1.51 | 1.15 |
| 2018 | 1.35 | 1.73 | 1.14 |
| 2017 | 2.12 | 2.84 | 1.53 |
| 2016 | 2.28 | 2.8 | 1.83 |
| 2015 | 3.76 | 6.1 | 2.24 |
| 2014 | 1.79 | 2.8 | 1.09 |
| 2013 | 1.78 | 3.03 | 1.17 |
| 2012 | 1.95 | 2.5 | 1.59 |
| 2011 | 2.51 | 3.64 | 1.64 |
| 2010 | 3.84 | 5.3 | 2.83 |
| 2009 | 3.76 | 5.79 | 2.2 |
| 2008 | 7.71 | 20.92 | 1.55 |
| 2007 | 8.94 | 12.83 | 4.67 |
| 2006 | 3.64 | 5.51 | 2.28 |
| 2005 | 1.79 | 2.56 | 0.95 |
| 2004 | 1.73 | 2.96 | 1.1 |