| 时间 | 平均 | 最高 | 最低 |
|---|---|---|---|
| 2025 | 0.9 | 1 | 0.82 |
| 2024 | 0.83 | 1.1 | 0.67 |
| 2023 | 1.02 | 1.21 | 0.81 |
| 2022 | 0.89 | 1.28 | 0.65 |
| 2021 | 1.35 | 2.03 | 0.99 |
| 2020 | 0.88 | 1.31 | 0.69 |
| 2019 | 1.04 | 1.47 | 0.81 |
| 2018 | 1.33 | 2.08 | 0.84 |
| 2017 | 1.94 | 2.39 | 1.7 |
| 2016 | 1.96 | 2.35 | 1.72 |
| 2015 | 2.79 | 4.48 | 1.92 |
| 2014 | 2.36 | 2.8 | 2.04 |
| 2013 | 2.52 | 3.05 | 2.04 |
| 2012 | 2.08 | 2.54 | 1.58 |
| 2011 | 3.64 | 4.96 | 2.2 |
| 2010 | 4.42 | 5.92 | 3.16 |
| 2009 | 4.16 | 5.24 | 2.43 |
| 2008 | 5.49 | 11.66 | 1.89 |
| 2007 | 6.13 | 10.63 | 2.21 |
| 2006 | 1.75 | 2.29 | 1.26 |
| 2005 | 1.41 | 1.88 | 1.06 |
| 2004 | 2.13 | 3.89 | 1.2 |