| 时间 | 平均 | 最高 | 最低 |
|---|---|---|---|
| 2025 | 1.21 | 1.39 | 0.92 |
| 2024 | 0.87 | 1.67 | 0.5 |
| 2023 | 1.28 | 1.44 | 1.09 |
| 2022 | 1.3 | 1.81 | 0.79 |
| 2021 | 0.74 | 1.36 | 0.59 |
| 2020 | 1.02 | 1.28 | 0.79 |
| 2019 | 1.16 | 1.41 | 1 |
| 2018 | 1.25 | 1.52 | 1.04 |
| 2017 | 1.61 | 1.91 | 1.3 |
| 2016 | 1.98 | 2.43 | 1.63 |
| 2015 | 2.11 | 4.52 | 1.1 |
| 2014 | 2.39 | 5.32 | 1.08 |
| 2013 | 1.49 | 5.04 | 0.85 |
| 2012 | 1.04 | 1.31 | 0.87 |
| 2011 | 1.48 | 1.98 | 0.92 |
| 2010 | 1.79 | 2.43 | 1.44 |
| 2009 | 1.08 | 1.79 | 0.58 |
| 2008 | 0.82 | 1.4 | 0.42 |
| 2007 | 1.17 | 1.64 | 0.67 |
| 2006 | 0.68 | 0.88 | 0.49 |
| 2005 | 1.03 | 1.55 | 0.53 |