| 时间 | 平均 | 最高 | 最低 |
|---|---|---|---|
| 2025 | 2.52 | 2.8 | 2.06 |
| 2024 | 2.14 | 2.7 | 1.72 |
| 2023 | 3.04 | 3.86 | 2.44 |
| 2022 | 4.32 | 8.58 | 2.91 |
| 2021 | 4.05 | 6.65 | 2.27 |
| 2020 | 3.63 | 4.88 | 2.53 |
| 2019 | 3 | 4.06 | 2.47 |
| 2018 | 3.39 | 5.11 | 1.77 |
| 2017 | 4.08 | 5.4 | 3.34 |
| 2016 | 6.11 | 12.43 | 3.91 |
| 2015 | 11.9 | 26.88 | 6.16 |
| 2014 | 5.16 | 8.46 | 3.56 |
| 2013 | 3.79 | 4.53 | 2.98 |
| 2012 | 3.57 | 4.45 | 2.36 |
| 2011 | 5.4 | 6.5 | 3.79 |
| 2010 | 6.2 | 7.62 | 4.33 |
| 2009 | 3.96 | 5.08 | 2.71 |
| 2008 | 3.02 | 5.27 | 1.37 |
| 2007 | 4.41 | 6.6 | 1.69 |
| 2006 | 1.7 | 1.96 | 1.42 |
| 2005 | 1.77 | 2.25 | 1.46 |
| 2004 | 2.37 | 3.27 | 1.77 |
| 2003 | 3.18 | 4.22 | 2.12 |
| 2002 | 5.22 | 6.19 | 4.38 |
| 2001 | 6.63 | 8.24 | 4.6 |
| 2000 | 6.64 | 8.61 | 3.63 |
| 1999 | 5.08 | 6.5 | 4.29 |
| 1998 | 5.79 | 7.46 | 4.13 |