| 时间 | 平均 | 最高 | 最低 |
|---|---|---|---|
| 2024 | 2.58 | 3.26 | 1.74 |
| 2023 | 2.1 | 2.58 | 1.64 |
| 2022 | 2.12 | 3.04 | 1.44 |
| 2021 | 1.93 | 3.45 | 1.43 |
| 2020 | 1.76 | 2.15 | 1.28 |
| 2019 | 1.26 | 1.61 | 1.01 |
| 2018 | 1.29 | 1.88 | 0.97 |
| 2017 | 2.43 | 3.07 | 1.8 |
| 2016 | 2.51 | 3.23 | 2.15 |
| 2015 | 4.24 | 6.34 | 2.55 |
| 2014 | 4.79 | 7.55 | 3.69 |
| 2013 | 4.7 | 6.1 | 3.2 |
| 2012 | 2.57 | 3.63 | 2 |
| 2011 | 4.49 | 6.19 | 2.93 |
| 2010 | 5 | 6.49 | 3.71 |
| 2009 | 3.31 | 4.47 | 2.11 |
| 2008 | 2.7 | 4.7 | 1.01 |
| 2007 | 2.9 | 3.41 | 1.76 |
| 2006 | 1.52 | 2.25 | 0.89 |
| 2005 | 1.1 | 1.86 | 0.76 |
| 2004 | 2.25 | 2.77 | 1.81 |
| 2003 | 2.23 | 2.49 | 2 |
| 2002 | 2.92 | 3.48 | 2.63 |
| 2001 | 4.22 | 5.52 | 2.7 |
| 2000 | 5.54 | 6.73 | 3.78 |
| 1999 | 5.43 | 7.4 | 3.14 |
| 1998 | 4.39 | 5.37 | 3.31 |