| 时间 | 平均 | 最高 | 最低 |
|---|---|---|---|
| 2025 | 1.18 | 1.34 | 1.01 |
| 2024 | 0.97 | 1.31 | 0.71 |
| 2023 | 1.16 | 1.41 | 1.02 |
| 2022 | 1.32 | 1.83 | 1.06 |
| 2021 | 1.54 | 1.86 | 1.33 |
| 2020 | 1.97 | 2.68 | 1.61 |
| 2019 | 1.66 | 2.31 | 1.29 |
| 2018 | 1.45 | 2.63 | 0.96 |
| 2017 | 2.53 | 3.23 | 2.08 |
| 2016 | 1.86 | 2.59 | 1.39 |
| 2015 | 2.31 | 3.67 | 1.4 |
| 2014 | 2.41 | 3.42 | 1.85 |
| 2013 | 2.13 | 2.71 | 1.81 |
| 2012 | 2.77 | 3.5 | 1.79 |
| 2011 | 3.61 | 4.75 | 1.98 |
| 2010 | 3.66 | 5.2 | 2.7 |
| 2009 | 2.13 | 2.96 | 1.33 |
| 2008 | 2.34 | 5.49 | 1.07 |
| 2007 | 3.87 | 5.41 | 2.18 |
| 2006 | 1.82 | 2.19 | 1.35 |
| 2005 | 1.69 | 2.49 | 1.16 |
| 2004 | 2.73 | 3.43 | 2.06 |
| 2003 | 2.73 | 3.41 | 1.99 |
| 2002 | 4.05 | 4.54 | 3.2 |
| 2001 | 5.27 | 6.44 | 3.71 |
| 2000 | 6.25 | 8.96 | 4.86 |
| 1999 | 5.35 | 7.55 | 4.4 |
| 1998 | 5.24 | 6.39 | 3.46 |