| 时间 | 平均 | 最高 | 最低 |
|---|---|---|---|
| 2024 | 1.74 | 2.21 | 1.37 |
| 2023 | 1.9 | 2.63 | 1.47 |
| 2022 | 2.09 | 2.54 | 1.64 |
| 2021 | 2.77 | 3.67 | 2.36 |
| 2020 | 2.51 | 3.2 | 1.83 |
| 2019 | 2.31 | 3.07 | 1.8 |
| 2018 | 2.41 | 3.51 | 1.78 |
| 2017 | 3.42 | 4.36 | 2.82 |
| 2016 | 2.92 | 3.75 | 2.48 |
| 2015 | 4.48 | 6.5 | 2.6 |
| 2014 | 2.34 | 3.91 | 1.79 |
| 2013 | 2.45 | 3.31 | 1.82 |
| 2012 | 3.36 | 4.02 | 2.66 |
| 2011 | 5.85 | 8.66 | 3.06 |
| 2010 | 7.58 | 10.85 | 5.11 |
| 2009 | 7.87 | 14.15 | 1.59 |
| 2008 | 4.37 | 12.49 | 1.25 |
| 2007 | 8.36 | 16.3 | 2.72 |
| 2006 | 2.54 | 3.98 | 1.44 |
| 2005 | 1.49 | 1.86 | 1.26 |
| 2004 | 2.18 | 3.07 | 1.69 |
| 2003 | 2.15 | 2.66 | 1.86 |
| 2002 | 2.38 | 2.86 | 1.77 |
| 2001 | 4.09 | 5.67 | 2.5 |
| 2000 | 5.03 | 5.66 | 4.51 |
| 1999 | 4.82 | 8.77 | 3.32 |