| 时间 | 平均 | 最高 | 最低 |
|---|---|---|---|
| 2024 | 2.54 | 3.02 | 2.04 |
| 2023 | 2.47 | 3.13 | 2 |
| 2022 | 2.96 | 4.15 | 2 |
| 2021 | 4.36 | 4.96 | 3.75 |
| 2020 | 3.41 | 4.16 | 2.8 |
| 2019 | 3.63 | 4.16 | 2.78 |
| 2018 | 3.45 | 4.35 | 2.81 |
| 2017 | 3 | 3.85 | 2.33 |
| 2016 | 2.25 | 2.5 | 1.93 |
| 2015 | 2.59 | 3.17 | 2.21 |
| 2014 | 1.99 | 2.78 | 1.76 |
| 2013 | 2.4 | 3.04 | 1.96 |
| 2012 | 2.52 | 3.24 | 2.02 |
| 2011 | 3.77 | 4.99 | 2.78 |
| 2010 | 5.7 | 7.23 | 4.4 |
| 2009 | 5.57 | 7.54 | 3.26 |
| 2008 | 8.41 | 17.94 | 3.14 |
| 2007 | 14.65 | 20.39 | 10.79 |
| 2006 | 6.4 | 11.64 | 4.97 |
| 2005 | 4.87 | 5.55 | 3.23 |
| 2004 | 6.77 | 9.8 | 5.01 |
| 2003 | 9.62 | 12.53 | 7.17 |