| 时间 | 平均 | 最高 | 最低 |
|---|---|---|---|
| 2025 | 0.43 | 0.5 | 0.38 |
| 2024 | 0.46 | 0.54 | 0.37 |
| 2023 | 0.41 | 0.46 | 0.38 |
| 2022 | 0.48 | 0.7 | 0.38 |
| 2021 | 0.61 | 0.82 | 0.39 |
| 2020 | 0.79 | 0.89 | 0.69 |
| 2019 | 0.92 | 1.1 | 0.78 |
| 2018 | 1.33 | 1.79 | 0.74 |
| 2017 | 2.55 | 4.54 | 1.73 |
| 2016 | 4.45 | 6.22 | 3.4 |
| 2015 | 1.52 | 5.79 | 0.37 |
| 2014 | 0.29 | 0.37 | 0.23 |
| 2013 | 0.26 | 0.32 | 0.17 |
| 2012 | 0.3 | 0.41 | 0.23 |
| 2011 | 22.85 | 86.91 | 0.36 |
| 2010 | 53.83 | 88.9 | 38.16 |
| 2009 | 22.99 | 45.43 | 6.45 |
| 2008 | 10.25 | 16.51 | 5.16 |
| 2007 | 10.84 | 19 | 4.76 |
| 2006 | 4.99 | 6.34 | 4.3 |
| 2005 | 5.22 | 7.15 | 3.91 |
| 2004 | 6.15 | 10.19 | 4.16 |