| 时间 | 平均 | 最高 | 最低 |
|---|---|---|---|
| 2025 | 1.06 | 1.13 | 0.92 |
| 2024 | 1.3 | 1.8 | 1.05 |
| 2023 | 1.81 | 2.7 | 1.51 |
| 2022 | 1.37 | 1.85 | 1.08 |
| 2021 | 1.12 | 1.43 | 0.91 |
| 2020 | 1.59 | 2.31 | 1.34 |
| 2019 | 1.76 | 2.44 | 1.49 |
| 2018 | 2.15 | 3.63 | 1.47 |
| 2017 | 4 | 5.05 | 2.95 |
| 2016 | 3.97 | 5.2 | 2.98 |
| 2015 | 5.08 | 8.71 | 2.92 |
| 2014 | 2.26 | 3.79 | 1.7 |
| 2013 | 1.98 | 2.27 | 1.7 |
| 2012 | 2.26 | 2.67 | 1.92 |
| 2011 | 3.07 | 3.69 | 2.12 |
| 2010 | 3.5 | 4.32 | 2.8 |
| 2009 | 3.54 | 4.63 | 2.27 |
| 2008 | 3.06 | 4.99 | 1.56 |
| 2007 | 4.01 | 6.95 | 1.81 |
| 2006 | 1.65 | 2.17 | 1.21 |
| 2005 | 1.53 | 2.46 | 1.06 |
| 2004 | 3.15 | 4.57 | 2.15 |
| 2003 | 4.19 | 5.31 | 3.09 |
| 2002 | 4.5 | 5.31 | 3.56 |
| 2001 | 5.27 | 5.72 | 4.19 |
| 2000 | 3.91 | 6.4 | 1.88 |
| 1999 | 1.62 | 1.96 | 1.37 |
| 1998 | 1.55 | 2.12 | 1.23 |
| 1997 | 1.66 | 2.48 | 1.27 |