| 时间 | 平均 | 最高 | 最低 |
|---|---|---|---|
| 2025 | 12.8 | 14.93 | 10.57 |
| 2024 | 8.14 | 16.52 | 4.56 |
| 2023 | 8.53 | 11.19 | 6.79 |
| 2022 | 7.59 | 9.1 | 5.6 |
| 2021 | 8.02 | 11.54 | 5.46 |
| 2020 | 4.45 | 6.07 | 3.28 |
| 2019 | 6.04 | 7.41 | 4.94 |
| 2018 | 6.96 | 11.44 | 4.18 |
| 2017 | 9.91 | 12.85 | 5.76 |
| 2016 | 6.3 | 9.45 | 4.23 |
| 2015 | 6.13 | 9.81 | 3.74 |
| 2014 | 2.97 | 5.69 | 1.47 |
| 2013 | 1.5 | 1.92 | 1.19 |
| 2012 | 1.77 | 2.4 | 1.33 |
| 2011 | 3.24 | 4.94 | 1.82 |
| 2010 | 2.75 | 3.39 | 2.28 |
| 2009 | 2.12 | 2.84 | 1.55 |
| 2008 | 2.34 | 4.47 | 1.22 |
| 2007 | 3.47 | 5.51 | 1.1 |
| 2006 | 1.02 | 1.17 | 0.86 |
| 2005 | 1.23 | 1.73 | 0.77 |
| 2004 | 2.2 | 3.68 | 1.53 |
| 2003 | 2.81 | 3.39 | 1.81 |
| 2002 | 3.05 | 3.71 | 1.98 |
| 2001 | 3.72 | 4.32 | 3 |
| 2000 | 4.31 | 5.91 | 3.47 |
| 1999 | 4.13 | 5.63 | 3.19 |
| 1998 | 8.21 | 11.38 | 5.29 |
| 1997 | 6.42 | 9.51 | 3.01 |