| 时间 | 平均 | 最高 | 最低 |
|---|---|---|---|
| 2025 | 1.09 | 1.17 | 1.01 |
| 2024 | 1.16 | 1.38 | 0.96 |
| 2023 | 1.13 | 1.43 | 0.77 |
| 2022 | 1.31 | 1.74 | 1.05 |
| 2021 | 1.34 | 2.15 | 0.9 |
| 2020 | 1.02 | 1.33 | 0.87 |
| 2019 | 1.18 | 1.47 | 1.03 |
| 2018 | 1.15 | 1.3 | 0.98 |
| 2017 | 1.55 | 1.94 | 1.13 |
| 2016 | 2.21 | 3.4 | 1.71 |
| 2015 | 3.09 | 5.03 | 2.11 |
| 2014 | 5.26 | 15.32 | 2.01 |
| 2013 | 2.14 | 3.52 | 1.74 |
| 2012 | 2.21 | 2.7 | 1.69 |
| 2011 | 3.2 | 4.16 | 2 |
| 2010 | 2.74 | 3.62 | 1.87 |
| 2009 | 2.1 | 2.82 | 1.22 |
| 2008 | 2.05 | 4.15 | 0.92 |
| 2007 | 3.13 | 5.54 | 1.21 |
| 2006 | 1.03 | 1.4 | 0.68 |
| 2005 | 0.81 | 1.01 | 0.64 |