| 时间 | 平均 | 最高 | 最低 |
|---|---|---|---|
| 2025 | 3.93 | 6.2 | 0.68 |
| 2024 | 4.24 | 7.01 | 2.04 |
| 2023 | 6.05 | 8.97 | 3.79 |
| 2022 | 4.27 | 6.55 | 3.27 |
| 2021 | 5.44 | 8.58 | 3.11 |
| 2020 | 8.76 | 19.58 | 0.95 |
| 2019 | 1.66 | 2.5 | 1.23 |
| 2018 | 2.42 | 3.73 | 1.32 |
| 2017 | 4.21 | 5.52 | 3.5 |
| 2016 | 4.89 | 5.64 | 4.09 |
| 2015 | 7.53 | 12.91 | 4.61 |
| 2014 | 4.79 | 5.73 | 4.13 |
| 2013 | 4.33 | 7.01 | 2.15 |
| 2012 | 2.32 | 2.79 | 1.93 |
| 2011 | 3.1 | 3.64 | 2.22 |
| 2010 | 5.61 | 10.65 | 3.36 |
| 2009 | 5.76 | 7.51 | 3.78 |
| 2008 | 6.21 | 14.51 | 1.93 |
| 2007 | 20.79 | 72.64 | 5.38 |
| 2006 | 4.46 | 9.48 | 1.64 |
| 2005 | 2.01 | 3.32 | 1.23 |
| 2004 | 3.34 | 4.72 | 2.26 |
| 2003 | 4.84 | 6.82 | 3.07 |
| 2002 | 5.92 | 6.64 | 4.31 |
| 2001 | 7.14 | 8.83 | 4.98 |
| 2000 | 5.46 | 7.56 | 3.59 |
| 1999 | 2.8 | 4.84 | 2.11 |
| 1998 | 2.91 | 4.3 | 2.11 |
| 1997 | 2.56 | 3.85 | 1.74 |