| 时间 | 平均 | 最高 | 最低 |
|---|---|---|---|
| 2025 | 1.33 | 1.41 | 1.23 |
| 2024 | 1.5 | 1.72 | 1.32 |
| 2023 | 1.33 | 1.57 | 1.19 |
| 2022 | 1.48 | 1.75 | 1.27 |
| 2021 | 1.15 | 1.99 | 0.88 |
| 2020 | 1.09 | 1.21 | 0.95 |
| 2019 | 1.32 | 1.71 | 1.05 |
| 2018 | 1.34 | 1.65 | 1.08 |
| 2017 | 1.75 | 2.08 | 1.57 |
| 2016 | 1.8 | 2.39 | 1.69 |
| 2015 | 2.83 | 4.89 | 1.93 |
| 2014 | 1.45 | 2.45 | 1.07 |
| 2013 | 1.56 | 2.13 | 1.08 |
| 2012 | 2.6 | 4.56 | 1.69 |
| 2011 | 4.16 | 5.34 | 3.25 |
| 2010 | 4.5 | 5.71 | 3.71 |
| 2009 | 3.57 | 5.39 | 1.49 |
| 2008 | 2.29 | 3.98 | 1.1 |
| 2007 | 3.18 | 4.62 | 1.34 |
| 2006 | 1.26 | 1.43 | 0.92 |
| 2005 | 1.48 | 1.89 | 1.2 |
| 2004 | 2.78 | 4.66 | 1.91 |
| 2003 | 3.56 | 4.25 | 1.73 |
| 2002 | 2.44 | 2.84 | 1.66 |
| 2001 | 2.59 | 3.02 | 1.9 |
| 2000 | 2.49 | 3.05 | 1.88 |
| 1999 | 3.66 | 7.17 | 1.84 |
| 1998 | 4.88 | 6.96 | 2.85 |
| 1997 | 3.91 | 5.92 | 2.35 |