| 时间 | 平均 | 最高 | 最低 |
|---|---|---|---|
| 2025 | 4.13 | 4.49 | 3.81 |
| 2024 | 4.24 | 5.35 | 2.87 |
| 2023 | 3.34 | 5.11 | 2.52 |
| 2022 | 2.97 | 3.96 | 2.41 |
| 2021 | 5.3 | 8.65 | 3.3 |
| 2020 | 1.99 | 7.21 | 0.72 |
| 2019 | 1.01 | 1.32 | 0.83 |
| 2018 | 1.67 | 3.19 | 0.83 |
| 2017 | 2.27 | 3.07 | 1.85 |
| 2016 | 2.54 | 3.13 | 2.05 |
| 2015 | 3.17 | 5.33 | 1.96 |
| 2014 | 1.86 | 2.37 | 1.6 |
| 2013 | 1.72 | 2.04 | 1.38 |
| 2012 | 1.59 | 2.07 | 1.29 |
| 2011 | 2.36 | 2.78 | 1.59 |
| 2010 | 2.27 | 3.01 | 1.66 |
| 2009 | 2.02 | 2.8 | 1.43 |
| 2008 | 2.53 | 5.47 | 1.04 |
| 2007 | 2.79 | 4.62 | 1.86 |
| 2006 | 1.22 | 2.15 | 0.87 |
| 2005 | 1.1 | 1.37 | 0.83 |
| 2004 | 1.6 | 2.19 | 1.26 |
| 2003 | 1.89 | 2.26 | 1.5 |
| 2002 | 2.49 | 2.71 | 2.03 |
| 2001 | 3.12 | 3.7 | 2.28 |
| 2000 | 3.27 | 3.83 | 2.64 |
| 1999 | 2.88 | 3.64 | 2.34 |