| 时间 | 平均 | 最高 | 最低 |
|---|---|---|---|
| 2025 | 2.48 | 2.83 | 2.19 |
| 2024 | 2.35 | 3.72 | 1.66 |
| 2023 | 2.27 | 2.94 | 1.87 |
| 2022 | 1.97 | 2.94 | 1.47 |
| 2021 | 2.15 | 2.95 | 1.76 |
| 2020 | 3.18 | 5.03 | 2.2 |
| 2019 | 2.54 | 5.12 | 1.74 |
| 2018 | 2.08 | 2.82 | 1.51 |
| 2017 | 3.64 | 6.28 | 2.62 |
| 2016 | 3.8 | 4.91 | 2.95 |
| 2015 | 4.8 | 7.59 | 3.24 |
| 2014 | 4.04 | 5.54 | 3.25 |
| 2013 | 2.82 | 6.95 | 1.61 |
| 2012 | 3.12 | 5.24 | 1.37 |
| 2011 | 4.4 | 6.25 | 2.79 |
| 2010 | 4.18 | 5.25 | 2.65 |
| 2009 | 4.39 | 5.61 | 2.62 |
| 2008 | 3.12 | 5.25 | 1.42 |
| 2007 | 5.2 | 7.73 | 2.64 |
| 2006 | 2.13 | 3.08 | 1.26 |
| 2005 | 1.72 | 2.32 | 1.13 |
| 2004 | 3.04 | 4.15 | 2.09 |
| 2003 | 3.59 | 4.32 | 2.36 |
| 2002 | 4.88 | 5.51 | 3.99 |
| 2001 | 6.44 | 8.39 | 4.91 |
| 2000 | 8.55 | 12.21 | 4.71 |
| 1999 | 4.92 | 7 | 3.5 |
| 1998 | 5 | 6.81 | 4.25 |
| 1997 | 6.17 | 9.85 | 4.42 |