| 时间 | 平均 | 最高 | 最低 |
|---|---|---|---|
| 2025 | 2.33 | 2.62 | 2.01 |
| 2024 | 1.8 | 2.59 | 1.3 |
| 2023 | 1.91 | 2.1 | 1.66 |
| 2022 | 1.81 | 2.34 | 1.35 |
| 2021 | 1.86 | 2.66 | 1.29 |
| 2020 | 1.55 | 1.94 | 1.23 |
| 2019 | 1.65 | 2.3 | 1.05 |
| 2018 | 1.46 | 2.03 | 0.93 |
| 2017 | 2.21 | 2.71 | 1.79 |
| 2016 | 3.04 | 3.96 | 2.31 |
| 2015 | 3.32 | 5.65 | 2.39 |
| 2014 | 2.35 | 2.79 | 1.73 |
| 2013 | 2.36 | 3.04 | 1.89 |
| 2012 | 3.6 | 4.84 | 2.27 |
| 2011 | 5.65 | 6.86 | 4.3 |
| 2010 | 6.01 | 8.49 | 4.47 |
| 2009 | 4.87 | 6.64 | 2.68 |
| 2008 | 3.7 | 6.12 | 1.41 |
| 2007 | 4.02 | 5.12 | 3 |
| 2006 | 2.25 | 3.55 | 1.35 |
| 2005 | 1.64 | 2.09 | 1.05 |
| 2004 | 2.26 | 2.85 | 1.9 |
| 2003 | 2.23 | 2.85 | 1.62 |
| 2002 | 3.39 | 4.04 | 2.63 |
| 2001 | 5.34 | 7.58 | 3.35 |