| 时间 | 平均 | 最高 | 最低 |
|---|---|---|---|
| 2024 | 2.1 | 3.21 | 1.25 |
| 2023 | 1.77 | 2.43 | 0.93 |
| 2022 | 2.49 | 3.32 | 1.8 |
| 2021 | 1.47 | 3.04 | 0.67 |
| 2020 | 0.7 | 0.86 | 0.61 |
| 2019 | 0.81 | 1 | 0.68 |
| 2018 | 1.09 | 1.8 | 0.72 |
| 2017 | 1.28 | 1.57 | 1.09 |
| 2016 | 1.34 | 1.63 | 1.05 |
| 2015 | 1.57 | 2.48 | 0.97 |
| 2014 | 0.97 | 1.66 | 0.74 |
| 2013 | 1.49 | 2.19 | 0.96 |
| 2012 | 2.38 | 3.29 | 1.72 |
| 2011 | 3.91 | 5.06 | 2.59 |
| 2010 | 3.53 | 5.16 | 2.45 |
| 2009 | 3.05 | 4.45 | 1.69 |
| 2008 | 3.96 | 6.34 | 1.57 |
| 2007 | 4.23 | 7.4 | 1.94 |
| 2006 | 1.9 | 2.38 | 1.59 |
| 2005 | 1.39 | 1.77 | 0.71 |
| 2004 | 2.25 | 3.01 | 1.53 |
| 2003 | 1.63 | 2.13 | 1.38 |
| 2002 | 2.1 | 2.28 | 1.89 |
| 2001 | 2.65 | 3.52 | 1.89 |
| 2000 | 2.66 | 3.26 | 2.02 |
| 1999 | 2.16 | 2.94 | 1.66 |