| 时间 | 平均 | 最高 | 最低 |
|---|---|---|---|
| 2025 | 3.55 | 4.13 | 3.2 |
| 2024 | 3.36 | 4.29 | 2.48 |
| 2023 | 3.93 | 6.17 | 3.22 |
| 2022 | 3.92 | 5.08 | 2.95 |
| 2021 | 2.57 | 5.55 | 1.2 |
| 2020 | 2.25 | 2.96 | 1.59 |
| 2019 | 2.02 | 2.72 | 1 |
| 2018 | 1.54 | 2.37 | 1.01 |
| 2017 | 2.69 | 4.67 | 1.7 |
| 2016 | 14.12 | 37.38 | 3.69 |
| 2015 | 5.59 | 8.44 | 2.61 |
| 2014 | 2.4 | 3.64 | 1.85 |
| 2013 | 2.32 | 3.1 | 1.8 |
| 2012 | 3.35 | 4.41 | 2.48 |
| 2011 | 8.22 | 16.95 | 3.5 |
| 2010 | 8.59 | 15.65 | 5.29 |
| 2009 | 5.32 | 7.97 | 2.22 |
| 2008 | 17.8 | 66.47 | 1.79 |
| 2007 | 33.74 | 52.53 | 16.39 |
| 2006 | 12.76 | 24.83 | 1.49 |
| 2005 | 2.15 | 3.29 | 1.55 |
| 2004 | 7.78 | 18.18 | 2.7 |
| 2003 | 15.88 | 18.87 | 11.74 |
| 2002 | 14.32 | 21.57 | 7.95 |
| 2001 | 8.71 | 10.6 | 7.14 |
| 2000 | 6.17 | 9.04 | 3.62 |
| 1999 | 3.07 | 4.17 | 2.28 |
| 1998 | 2.98 | 4.17 | 2.21 |
| 1997 | 3.46 | 4.88 | 2.85 |