| 时间 | 平均 | 最高 | 最低 |
|---|---|---|---|
| 2025 | 1.16 | 1.34 | 0.81 |
| 2024 | 1.18 | 1.6 | 0.92 |
| 2023 | 1.41 | 1.65 | 1.2 |
| 2022 | 1.71 | 2.4 | 1.07 |
| 2021 | 1.83 | 2.25 | 1.55 |
| 2020 | 1.75 | 2.34 | 1.32 |
| 2019 | 1.35 | 1.79 | 0.63 |
| 2018 | 1.89 | 3.22 | 0.68 |
| 2017 | 2.85 | 3.71 | 2.21 |
| 2016 | 3.12 | 3.76 | 2.46 |
| 2015 | 6.18 | 10.3 | 3.59 |
| 2014 | 3.81 | 4.52 | 2.79 |
| 2013 | 2.65 | 3.42 | 2.1 |
| 2012 | 2.8 | 3.81 | 2.09 |
| 2011 | 4 | 5.49 | 3.06 |
| 2010 | 4.5 | 5.99 | 3.65 |
| 2009 | 3.81 | 5.3 | 2.98 |
| 2008 | 4.55 | 9.31 | 1.7 |
| 2007 | 9.56 | 14.69 | 6.61 |
| 2006 | 4.23 | 6.98 | 2.52 |
| 2005 | 3.08 | 3.96 | 2.46 |
| 2004 | 4.77 | 7.13 | 3.37 |
| 2003 | 8 | 16.17 | 4.59 |