| 时间 | 平均 | 最高 | 最低 |
|---|---|---|---|
| 2025 | 1.75 | 2.24 | 1.54 |
| 2024 | 1.49 | 2 | 1.03 |
| 2023 | 1.58 | 1.84 | 1.25 |
| 2022 | 1.68 | 2.35 | 1.2 |
| 2021 | 1.6 | 2.4 | 1.23 |
| 2020 | 1.26 | 1.55 | 0.98 |
| 2019 | 1.45 | 2.16 | 1.06 |
| 2018 | 1.31 | 1.72 | 1 |
| 2017 | 2.03 | 2.71 | 1.67 |
| 2016 | 2.77 | 3.86 | 2 |
| 2015 | 4.49 | 10.17 | 2.91 |
| 2014 | 2.18 | 2.72 | 1.77 |
| 2013 | 3.11 | 4.05 | 2.13 |
| 2012 | 3.69 | 4.59 | 3.08 |
| 2011 | 6.67 | 11.03 | 3.4 |
| 2010 | 9.33 | 13.89 | 5.21 |
| 2009 | 6.59 | 8.89 | 4.72 |
| 2008 | 5.37 | 9.91 | 3.31 |
| 2007 | 8.17 | 11.44 | 4.56 |
| 2006 | 2.88 | 4.68 | 1.93 |
| 2005 | 1.95 | 2.74 | 1.3 |
| 2004 | 3.73 | 5.69 | 2.46 |
| 2003 | 4.9 | 16.98 | 3.66 |