| 时间 | 平均 | 最高 | 最低 |
|---|---|---|---|
| 2025 | 2.28 | 2.53 | 2.11 |
| 2024 | 2.29 | 2.89 | 1.74 |
| 2023 | 3 | 3.47 | 2.56 |
| 2022 | 3.52 | 6.79 | 2.68 |
| 2021 | 2.97 | 3.4 | 2.58 |
| 2020 | 3.28 | 3.94 | 2.87 |
| 2019 | 3.19 | 4.83 | 2.51 |
| 2018 | 3.42 | 4.53 | 2.36 |
| 2017 | 5.77 | 7.56 | 4.39 |
| 2016 | 7.02 | 8.76 | 5.75 |
| 2015 | 9.34 | 12.23 | 5.51 |
| 2014 | 7.99 | 11.43 | 6.12 |
| 2013 | 6.38 | 8.32 | 3.67 |
| 2012 | 3.89 | 4.81 | 2.81 |
| 2011 | 6.84 | 10.58 | 4.13 |
| 2010 | 9.44 | 12.28 | 5.94 |
| 2009 | 6.15 | 10.44 | 3.67 |
| 2008 | 4.77 | 8.26 | 2.93 |
| 2007 | 6.15 | 9.89 | 3.14 |
| 2006 | 3.19 | 3.82 | 2.46 |
| 2005 | 3.27 | 4.68 | 2.32 |
| 2004 | 7.31 | 19.23 | 4.45 |
| 2003 | 9.38 | 15.7 | 4.54 |
| 2002 | 5.75 | 7.03 | 3.83 |
| 2001 | 6.8 | 8.11 | 4.61 |
| 2000 | 4.8 | 6.62 | 3.2 |
| 1999 | 3.04 | 4.06 | 2.38 |
| 1998 | 3.43 | 4.21 | 2.54 |