| 时间 | 平均 | 最高 | 最低 |
|---|---|---|---|
| 2025 | 4.96 | 5.53 | 4.59 |
| 2024 | 4.4 | 5.72 | 3.72 |
| 2023 | 5.79 | 6.61 | 4.63 |
| 2022 | 6.89 | 9.92 | 4.74 |
| 2021 | 9.61 | 12.78 | 7.22 |
| 2020 | 6.22 | 9.64 | 3.67 |
| 2019 | 3.32 | 4.34 | 2.15 |
| 2018 | 2.74 | 3.77 | 1.85 |
| 2017 | 4.43 | 5.41 | 3.6 |
| 2016 | 9.59 | 26.25 | 4.86 |
| 2015 | 12.88 | 29.49 | 5.38 |
| 2014 | 2.74 | 7.32 | 1.46 |
| 2013 | 1.71 | 1.99 | 1.44 |
| 2012 | 2.21 | 3.1 | 1.56 |
| 2011 | 3.27 | 4.29 | 2.18 |
| 2010 | 5.97 | 11.94 | 3.08 |
| 2009 | 8.19 | 11.38 | 4.14 |
| 2008 | 10.04 | 23.04 | 3.01 |
| 2007 | 21.95 | 31.52 | 7.89 |
| 2006 | 4.5 | 7.89 | 2.62 |
| 2005 | 3.48 | 5.06 | 2.34 |
| 2004 | 6.4 | 10.74 | 4.69 |
| 2003 | 7.5 | 11.55 | 2.26 |
| 2002 | 2.56 | 3.54 | 1.08 |
| 2001 | 3.35 | 4.61 | 2.18 |
| 2000 | 8.84 | 16.79 | 3.33 |
| 1999 | 15.69 | 24.65 | 6.27 |
| 1998 | 5.51 | 7.94 | 3.11 |
| 1997 | 3.19 | 4.53 | 2.14 |