| 时间 | 平均 | 最高 | 最低 |
|---|---|---|---|
| 2025 | 1.49 | 2.32 | 1.15 |
| 2024 | 1.35 | 1.67 | 1.12 |
| 2023 | 1.34 | 1.59 | 1.13 |
| 2022 | 1.49 | 2.17 | 1.07 |
| 2021 | 1.72 | 2.82 | 1.24 |
| 2020 | 1.26 | 1.57 | 1.07 |
| 2019 | 1.35 | 1.69 | 1.16 |
| 2018 | 1.43 | 1.83 | 1.17 |
| 2017 | 1.98 | 2.68 | 1.64 |
| 2016 | 1.89 | 2.38 | 1.56 |
| 2015 | 2.16 | 2.85 | 1.65 |
| 2014 | 1.32 | 1.95 | 1.09 |
| 2013 | 1.79 | 2.7 | 1.28 |
| 2012 | 2.7 | 3.22 | 2.2 |
| 2011 | 4.14 | 6.69 | 2.3 |
| 2010 | 4.21 | 6.65 | 2.91 |
| 2009 | 3.86 | 5.79 | 1.56 |
| 2008 | 3.36 | 8.1 | 1.27 |
| 2007 | 5.19 | 12.24 | 1.48 |
| 2006 | 1.37 | 1.83 | 1.03 |
| 2005 | 1.24 | 1.61 | 0.88 |
| 2004 | 2.17 | 3.11 | 1.46 |
| 2003 | 1.68 | 2.16 | 1.48 |
| 2002 | 1.72 | 1.86 | 1.37 |
| 2001 | 2.15 | 2.56 | 1.62 |
| 2000 | 3.25 | 3.9 | 2.62 |
| 1999 | 2.65 | 3.24 | 2.08 |
| 1998 | 4.62 | 9.06 | 2.27 |
| 1997 | 6.75 | 8.49 | 3.77 |