| 时间 | 平均 | 最高 | 最低 |
|---|---|---|---|
| 2025 | 1.46 | 1.88 | 1.15 |
| 2024 | 1.14 | 1.3 | 0.94 |
| 2023 | 1.31 | 1.54 | 1.13 |
| 2022 | 1.34 | 1.85 | 1.06 |
| 2021 | 1.74 | 2.21 | 1.31 |
| 2020 | 1.78 | 2.66 | 0.96 |
| 2019 | 2.13 | 4.55 | 1.01 |
| 2018 | 1.81 | 2.66 | 1.17 |
| 2017 | 2.99 | 3.53 | 2.33 |
| 2016 | 3.13 | 4.27 | 2.6 |
| 2015 | 2.26 | 4.69 | 1.21 |
| 2014 | 0.92 | 1.3 | 0.58 |
| 2013 | 0.59 | 0.73 | 0.45 |
| 2012 | 0.6 | 0.83 | 0.39 |
| 2011 | 1.06 | 1.47 | 0.67 |
| 2010 | 1.79 | 3.01 | 1.17 |
| 2009 | 1.22 | 2.15 | 0.52 |
| 2008 | 0.75 | 1.41 | 0.37 |
| 2007 | 2.01 | 4.44 | 0.98 |
| 2006 | 3.29 | 4.2 | 1.53 |
| 2005 | 2.62 | 3.91 | 1.53 |
| 2004 | 3.41 | 6.19 | 1.71 |