| 时间 | 平均 | 最高 | 最低 |
|---|---|---|---|
| 2025 | 2.05 | 2.27 | 1.79 |
| 2024 | 1.67 | 2.78 | 1.24 |
| 2023 | 1.46 | 1.78 | 1.1 |
| 2022 | 1.2 | 1.31 | 1.08 |
| 2021 | 1.28 | 1.68 | 0.91 |
| 2020 | 0.87 | 1.81 | 0.54 |
| 2019 | 0.73 | 0.95 | 0.64 |
| 2018 | 0.72 | 0.95 | 0.53 |
| 2017 | 1.05 | 1.45 | 0.7 |
| 2016 | 1.39 | 1.7 | 1.15 |
| 2015 | 2.03 | 2.74 | 1.52 |
| 2014 | 1.47 | 1.96 | 1.18 |
| 2013 | 1.2 | 1.69 | 0.95 |
| 2012 | 1.04 | 1.28 | 0.84 |
| 2011 | 1.88 | 2.79 | 0.95 |
| 2010 | 3.28 | 5.81 | 2.04 |
| 2009 | 3.74 | 5.07 | 2.65 |
| 2008 | 3.73 | 5.93 | 1.63 |
| 2007 | 4.26 | 6.34 | 2.23 |
| 2006 | 2.3 | 2.66 | 1.88 |
| 2005 | 2.46 | 3.71 | 1.72 |