| 时间 | 平均 | 最高 | 最低 |
|---|---|---|---|
| 2025 | 2.49 | 2.67 | 2.3 |
| 2024 | 2.32 | 3.06 | 1.78 |
| 2023 | 2.06 | 2.3 | 1.82 |
| 2022 | 1.69 | 2.18 | 1.48 |
| 2021 | 1.86 | 3.11 | 1.46 |
| 2020 | 1.83 | 2.42 | 1.6 |
| 2019 | 2.21 | 2.55 | 1.89 |
| 2018 | 2.27 | 2.86 | 1.91 |
| 2017 | 3.13 | 3.48 | 2.67 |
| 2016 | 3.19 | 4.11 | 2.42 |
| 2015 | 3.01 | 3.87 | 2.02 |
| 2014 | 2.2 | 3.08 | 1.9 |
| 2013 | 2.29 | 2.8 | 1.87 |
| 2012 | 2.3 | 2.52 | 2.02 |
| 2011 | 2.22 | 2.62 | 2.04 |
| 2010 | 2.56 | 2.95 | 1.97 |
| 2009 | 2.42 | 3.28 | 1.75 |
| 2008 | 2.98 | 5.85 | 1.46 |
| 2007 | 5.68 | 9.8 | 3.71 |
| 2006 | 2.13 | 3.96 | 1.5 |
| 2005 | 1.5 | 1.79 | 1.21 |
| 2004 | 2.03 | 2.51 | 1.72 |
| 2003 | 2.26 | 2.85 | 1.92 |
| 2002 | 3.23 | 3.84 | 2.5 |
| 2001 | 4.32 | 5.1 | 3.16 |
| 2000 | 3.91 | 4.98 | 2.84 |