| 时间 | 平均 | 最高 | 最低 |
|---|---|---|---|
| 2025 | 1.38 | 1.74 | 1.09 |
| 2024 | 1.13 | 1.47 | 0.82 |
| 2023 | 1.34 | 1.67 | 1.14 |
| 2022 | 1.51 | 2.31 | 1.14 |
| 2021 | 1.47 | 2 | 1.33 |
| 2020 | 1.72 | 2.17 | 1.47 |
| 2019 | 1.71 | 2.29 | 1.35 |
| 2018 | 1.83 | 2.4 | 1.26 |
| 2017 | 2.68 | 3.28 | 2.15 |
| 2016 | 3.56 | 6.32 | 2.75 |
| 2015 | 5.02 | 8.11 | 2.73 |
| 2014 | 3.22 | 4.25 | 2.55 |
| 2013 | 2.51 | 4.23 | 1.83 |
| 2012 | 2.12 | 2.51 | 1.61 |
| 2011 | 3.36 | 4.97 | 2.16 |
| 2010 | 5.35 | 7.11 | 3.69 |
| 2009 | 5.04 | 6.15 | 3.2 |
| 2008 | 5.8 | 12.81 | 2.43 |
| 2007 | 7.53 | 9.55 | 4.64 |
| 2006 | 2.61 | 4.85 | 1.7 |
| 2005 | 1.59 | 2.12 | 1.04 |
| 2004 | 2.57 | 3.32 | 1.95 |
| 2003 | 2.91 | 3.77 | 2.16 |
| 2002 | 4.64 | 5.61 | 3.95 |
| 2001 | 6.85 | 9.58 | 4.79 |
| 2000 | 8.57 | 10.15 | 6.53 |
| 1999 | 10.34 | 16.95 | 7.3 |
| 1998 | 14.36 | 23.96 | 8.18 |
| 1997 | 14.51 | 22.61 | 6.72 |