| 时间 | 平均 | 最高 | 最低 |
|---|---|---|---|
| 2025 | 0.52 | 0.58 | 0.42 |
| 2024 | 0.39 | 0.6 | 0.31 |
| 2023 | 0.42 | 0.48 | 0.36 |
| 2022 | 0.53 | 0.84 | 0.38 |
| 2021 | 0.96 | 1.29 | 0.73 |
| 2020 | 1.03 | 1.37 | 0.77 |
| 2019 | 1.19 | 1.51 | 0.79 |
| 2018 | 2.07 | 3.65 | 0.83 |
| 2017 | 6.07 | 10.44 | 3.01 |
| 2016 | 11.17 | 15.34 | 9.6 |
| 2015 | 3.29 | 17.98 | 0.88 |
| 2014 | 1.07 | 1.45 | 0.89 |
| 2013 | 1.22 | 1.48 | 1.02 |
| 2012 | 1.23 | 1.41 | 1.03 |
| 2011 | 1.95 | 2.76 | 1.08 |
| 2010 | 1.64 | 2.14 | 1.23 |
| 2009 | 1.06 | 1.4 | 0.74 |
| 2008 | 1.69 | 4.23 | 0.55 |
| 2007 | 2.85 | 3.77 | 1.59 |
| 2006 | 1.26 | 1.69 | 1.03 |
| 2005 | 1.27 | 1.66 | 0.94 |