| 时间 | 平均 | 最高 | 最低 |
|---|---|---|---|
| 2025 | 1.89 | 1.99 | 1.77 |
| 2024 | 2.25 | 2.9 | 1.62 |
| 2023 | 3.17 | 3.95 | 2.55 |
| 2022 | 3.23 | 4 | 2.36 |
| 2021 | 3.59 | 5.04 | 2.9 |
| 2020 | 2.85 | 5.06 | 1.94 |
| 2019 | 2.91 | 4.09 | 2.41 |
| 2018 | 3.88 | 6.31 | 2.33 |
| 2017 | 4.46 | 5.64 | 3.44 |
| 2016 | 3.32 | 4.12 | 2.45 |
| 2015 | 3.42 | 4.84 | 2.37 |
| 2014 | 2.92 | 3.4 | 2.48 |
| 2013 | 3.88 | 5.86 | 3.06 |
| 2012 | 4.83 | 6.1 | 3.4 |
| 2011 | 5.39 | 6.8 | 3.7 |
| 2010 | 6.91 | 8.6 | 5.45 |
| 2009 | 4.12 | 5.97 | 2.56 |
| 2008 | 4.06 | 7.88 | 1.93 |
| 2007 | 5.05 | 7.36 | 3.08 |
| 2006 | 2.55 | 3.83 | 1.65 |
| 2005 | 1.72 | 2.08 | 1.46 |
| 2004 | 2.52 | 4.06 | 1.86 |
| 2003 | 2.69 | 3.16 | 2.21 |
| 2002 | 3.72 | 4.18 | 3.26 |
| 2001 | 4.84 | 5.74 | 3.43 |
| 2000 | 4.59 | 5.48 | 4.04 |