| 时间 | 平均 | 最高 | 最低 |
|---|---|---|---|
| 2025 | 0.33 | 0.37 | 0.3 |
| 2024 | 0.3 | 0.39 | 0.24 |
| 2023 | 0.45 | 0.6 | 0.32 |
| 2022 | 0.57 | 0.71 | 0.46 |
| 2021 | 0.66 | 0.79 | 0.57 |
| 2020 | 0.94 | 1.33 | 0.65 |
| 2019 | 1.63 | 2.35 | 1.19 |
| 2018 | 1.63 | 2.29 | 1.26 |
| 2017 | 2.98 | 3.71 | 2.12 |
| 2016 | 2.68 | 3.64 | 2.31 |
| 2015 | 2.53 | 3.99 | 1.58 |
| 2014 | 3.38 | 5.81 | 1.75 |
| 2013 | 5.62 | 8.22 | 4.55 |
| 2012 | 3.67 | 4.73 | 3.13 |
| 2011 | 5.03 | 7.09 | 3.21 |
| 2010 | 3.12 | 4.85 | 2.07 |
| 2009 | 3.81 | 4.92 | 3.03 |
| 2008 | 3.67 | 6.21 | 2.09 |
| 2007 | 3.58 | 6.92 | 1.4 |
| 2006 | 1.33 | 1.51 | 1.19 |
| 2005 | 1.36 | 1.66 | 1.07 |