| 时间 | 平均 | 最高 | 最低 |
|---|---|---|---|
| 2025 | 1.01 | 1.19 | 0.76 |
| 2024 | 0.87 | 1.21 | 0.65 |
| 2023 | 1 | 1.19 | 0.83 |
| 2022 | 1.47 | 2.06 | 0.96 |
| 2021 | 3.05 | 9.13 | 1.13 |
| 2020 | 1.19 | 1.78 | 0.79 |
| 2019 | 0.96 | 1.39 | 0.69 |
| 2018 | 1.17 | 1.96 | 0.65 |
| 2017 | 2.04 | 2.85 | 1.62 |
| 2016 | 1.99 | 2.42 | 1.33 |
| 2015 | 2.22 | 3.49 | 1.29 |
| 2014 | 1.44 | 2.11 | 1.09 |
| 2013 | 1.24 | 1.49 | 0.99 |
| 2012 | 1.66 | 2.07 | 1.21 |
| 2011 | 3.68 | 7.13 | 1.57 |
| 2010 | 5.78 | 7.41 | 4.28 |
| 2009 | 4.05 | 7.15 | 1.54 |
| 2008 | 4.05 | 10.1 | 1.27 |
| 2007 | 7.93 | 17.4 | 1.87 |
| 2006 | 1.56 | 2.23 | 0.95 |
| 2005 | 1.1 | 1.5 | 0.84 |
| 2004 | 2.11 | 3.25 | 1.5 |
| 2003 | 2.35 | 2.95 | 1.9 |