| 时间 | 平均 | 最高 | 最低 |
|---|---|---|---|
| 2025 | 1.02 | 1.13 | 0.9 |
| 2024 | 0.99 | 1.51 | 0.7 |
| 2023 | 2.02 | 2.49 | 1.13 |
| 2022 | 1.64 | 2.49 | 1.3 |
| 2021 | 0.99 | 1.78 | 0.58 |
| 2020 | 0.48 | 0.77 | 0.33 |
| 2019 | 0.47 | 0.62 | 0.38 |
| 2018 | 0.75 | 0.99 | 0.47 |
| 2017 | 1.22 | 1.49 | 0.96 |
| 2016 | 1.21 | 1.5 | 1.03 |
| 2015 | 1.53 | 2.29 | 1 |
| 2014 | 0.77 | 1.3 | 0.63 |
| 2013 | 0.89 | 1.08 | 0.79 |
| 2012 | 0.78 | 0.93 | 0.64 |
| 2011 | 1.3 | 1.84 | 0.73 |
| 2010 | 1.71 | 2.45 | 1.25 |
| 2009 | 1.32 | 1.69 | 0.83 |
| 2008 | 1.64 | 3.52 | 0.63 |
| 2007 | 2.17 | 3.56 | 1.17 |
| 2006 | 0.69 | 1.42 | 0.17 |
| 2005 | 0.16 | 0.19 | 0.13 |
| 2004 | 0.27 | 0.53 | 0.17 |