| 时间 | 平均 | 最高 | 最低 |
|---|---|---|---|
| 2025 | 0.45 | 0.48 | 0.43 |
| 2024 | 0.42 | 0.5 | 0.36 |
| 2023 | 0.5 | 0.65 | 0.4 |
| 2022 | 0.72 | 0.94 | 0.54 |
| 2021 | 1.38 | 2.57 | 0.72 |
| 2020 | 1.1 | 1.57 | 0.79 |
| 2019 | 1.39 | 1.99 | 1.06 |
| 2018 | 2.42 | 3.5 | 1.27 |
| 2017 | 1.24 | 1.68 | 0.78 |
| 2016 | 6.16 | 25.51 | 1.6 |
| 2015 | 5.45 | 10.36 | 2.37 |
| 2014 | 2.13 | 2.74 | 1.22 |
| 2013 | 1.18 | 1.37 | 0.93 |
| 2012 | 1.68 | 2.5 | 1.05 |
| 2011 | 3.65 | 5.68 | 1.97 |
| 2010 | 4.61 | 6.77 | 3.19 |
| 2009 | 3.2 | 5.16 | 1.18 |
| 2008 | 1.94 | 4.24 | 0.89 |
| 2007 | 2.82 | 4.46 | 1.2 |
| 2006 | 1.57 | 2.1 | 1.14 |
| 2005 | 1.43 | 1.91 | 0.92 |
| 2004 | 1.73 | 3.2 | 1.13 |