| 时间 | 平均 | 最高 | 最低 |
|---|---|---|---|
| 2025 | 1.36 | 1.43 | 1.26 |
| 2024 | 1.71 | 2.7 | 1.3 |
| 2023 | 1.12 | 2.35 | 0.87 |
| 2022 | 1.04 | 1.57 | 0.86 |
| 2021 | 1.2 | 1.55 | 0.89 |
| 2020 | 1.73 | 2.51 | 1.22 |
| 2019 | 1.15 | 1.47 | 0.87 |
| 2018 | 1.22 | 1.84 | 0.86 |
| 2017 | 1.51 | 1.83 | 1.18 |
| 2016 | 1.18 | 1.44 | 1.01 |
| 2015 | 1.59 | 2.27 | 0.97 |
| 2014 | 1.3 | 1.86 | 1.16 |
| 2013 | 1.64 | 2.51 | 1.26 |
| 2012 | 1.79 | 2.37 | 1.41 |
| 2011 | 2.9 | 4.53 | 1.44 |
| 2010 | 3.45 | 4.26 | 2.39 |
| 2009 | 4.07 | 6.3 | 2.79 |
| 2008 | 3.11 | 5.43 | 1.58 |
| 2007 | 3.8 | 6.23 | 1.38 |
| 2006 | 1.26 | 1.79 | 0.88 |
| 2005 | 1.05 | 1.47 | 0.75 |
| 2004 | 2.18 | 3.62 | 1.44 |
| 2003 | 3.2 | 3.74 | 2.73 |
| 2002 | 4.36 | 4.94 | 3.71 |
| 2001 | 5.9 | 6.97 | 4.33 |
| 2000 | 6.88 | 10.51 | 3.67 |
| 1999 | 3.88 | 4.63 | 3.2 |
| 1998 | 4.83 | 6.59 | 3.21 |
| 1997 | 5.49 | 8.78 | 3.94 |