| 时间 | 平均 | 最高 | 最低 |
|---|---|---|---|
| 2025 | 0.22 | 0.25 | 0.2 |
| 2024 | 0.23 | 0.27 | 0.19 |
| 2023 | 0.28 | 0.36 | 0.23 |
| 2022 | 0.3 | 0.42 | 0.23 |
| 2021 | 0.41 | 0.53 | 0.33 |
| 2020 | 0.43 | 0.66 | 0.27 |
| 2019 | 0.37 | 0.62 | 0.22 |
| 2018 | 0.28 | 0.41 | 0.19 |
| 2017 | 0.5 | 0.69 | 0.38 |
| 2016 | 0.68 | 1.05 | 0.46 |
| 2015 | 0.84 | 1.24 | 0.49 |
| 2014 | 0.75 | 0.94 | 0.61 |
| 2013 | 0.84 | 1.32 | 0.63 |
| 2012 | 0.96 | 1.17 | 0.74 |
| 2011 | 1.69 | 2.77 | 0.88 |
| 2010 | 2.51 | 3.31 | 1.8 |
| 2009 | 2.27 | 3.38 | 0.7 |
| 2008 | 2 | 5.19 | 0.57 |
| 2007 | 5.19 | 7.42 | 2.95 |
| 2006 | 2.66 | 4.18 | 1.67 |
| 2005 | 1.8 | 2.74 | 1.3 |
| 2004 | 2.38 | 4.6 | 1.41 |