| 时间 | 平均 | 最高 | 最低 |
|---|---|---|---|
| 2025 | 0.31 | 0.34 | 0.28 |
| 2024 | 0.32 | 0.46 | 0.26 |
| 2023 | 0.4 | 0.52 | 0.35 |
| 2022 | 0.37 | 0.51 | 0.31 |
| 2021 | 0.44 | 0.64 | 0.33 |
| 2020 | 0.76 | 1.09 | 0.62 |
| 2019 | 1.22 | 2.04 | 0.66 |
| 2018 | 0.79 | 1.03 | 0.58 |
| 2017 | 0.87 | 0.96 | 0.75 |
| 2016 | 1.23 | 1.91 | 0.94 |
| 2015 | 2.55 | 4.82 | 1.6 |
| 2014 | 0.83 | 1.68 | 0.56 |
| 2013 | 0.93 | 1.49 | 0.68 |
| 2012 | 1.47 | 2.42 | 1.08 |
| 2011 | 4.17 | 5.8 | 1.81 |
| 2010 | 8.44 | 19.99 | 5.29 |
| 2009 | 18.57 | 28.96 | 8.15 |
| 2008 | 27.88 | 84.16 | 5.91 |
| 2007 | 57.18 | 107.26 | 17.58 |
| 2006 | 13.02 | 19.84 | 7.72 |
| 2005 | 6.32 | 8.6 | 4.4 |
| 2004 | 8.13 | 14.87 | 5.72 |