| 时间 | 平均 | 最高 | 最低 |
|---|---|---|---|
| 2025 | 1.46 | 1.68 | 1.3 |
| 2024 | 1.44 | 1.93 | 1.16 |
| 2023 | 1.79 | 2.19 | 1.47 |
| 2022 | 1.49 | 3.2 | 1.09 |
| 2021 | 1.14 | 1.51 | 0.84 |
| 2020 | 1.42 | 1.94 | 1.03 |
| 2019 | 1.45 | 2.21 | 1 |
| 2018 | 1.45 | 1.91 | 1 |
| 2017 | 2.6 | 3.79 | 1.78 |
| 2016 | 3.58 | 4.75 | 3.16 |
| 2015 | 5.1 | 6.83 | 3.17 |
| 2014 | 4.06 | 4.97 | 3.15 |
| 2013 | 12.97 | 35.86 | 3.37 |
| 2012 | 10.14 | 16.62 | 5.48 |
| 2011 | 10.13 | 12.87 | 6.4 |
| 2010 | 10.07 | 11.42 | 8.43 |
| 2009 | 8.35 | 11.09 | 4.55 |
| 2008 | 7.54 | 13.87 | 3.16 |
| 2007 | 12.81 | 19.85 | 8 |
| 2006 | 8.41 | 12.94 | 5.73 |
| 2005 | 4.6 | 6.77 | 3.29 |
| 2004 | 6.35 | 8.62 | 4 |
| 2003 | 7.86 | 11 | 4.71 |
| 2002 | 7.2 | 8.66 | 4.86 |
| 2001 | 7.87 | 11.6 | 5.62 |
| 2000 | 5.43 | 8.15 | 3.86 |
| 1999 | 4.04 | 5.26 | 3.33 |
| 1998 | 3.4 | 4.18 | 2.37 |
| 1997 | 2.2 | 2.76 | 1.7 |