| 时间 | 平均 | 最高 | 最低 |
|---|---|---|---|
| 2025 | 1.48 | 2 | 1.35 |
| 2024 | 1.22 | 1.92 | 0.9 |
| 2023 | 1.45 | 1.64 | 1.23 |
| 2022 | 1.63 | 2.21 | 1.34 |
| 2021 | 1.38 | 1.6 | 1.25 |
| 2020 | 1.34 | 1.78 | 1.14 |
| 2019 | 1.31 | 1.58 | 1.12 |
| 2018 | 1.44 | 1.84 | 1.13 |
| 2017 | 2.49 | 3.93 | 1.67 |
| 2016 | 3.2 | 5.04 | 2.73 |
| 2015 | 4.07 | 8.16 | 2.11 |
| 2014 | 2.05 | 2.59 | 1.64 |
| 2013 | 1.86 | 2.18 | 1.59 |
| 2012 | 1.77 | 2.18 | 1.46 |
| 2011 | 2.85 | 3.74 | 1.7 |
| 2010 | 3.91 | 4.91 | 3.07 |
| 2009 | 3.46 | 5.37 | 2.01 |
| 2008 | 4.04 | 7 | 1.64 |
| 2007 | 5.98 | 7.64 | 3.97 |
| 2006 | 3.13 | 3.92 | 2.09 |
| 2005 | 1.65 | 2.19 | 1.43 |
| 2004 | 1.93 | 2.52 | 1.64 |
| 2003 | 2.25 | 2.75 | 1.76 |
| 2002 | 3.18 | 3.56 | 2.51 |
| 2001 | 4.18 | 4.9 | 3.19 |
| 2000 | 4.07 | 5.12 | 2.53 |
| 1999 | 2.87 | 3.46 | 2.48 |
| 1998 | 3.39 | 5.23 | 2.47 |
| 1997 | 4.33 | 5.89 | 2.86 |