| 时间 | 平均 | 最高 | 最低 |
|---|---|---|---|
| 2025 | 0.42 | 0.63 | 0.34 |
| 2024 | 0.35 | 0.51 | 0.27 |
| 2023 | 0.41 | 0.63 | 0.33 |
| 2022 | 0.58 | 0.82 | 0.41 |
| 2021 | 0.97 | 1.2 | 0.79 |
| 2020 | 1.39 | 1.99 | 1.03 |
| 2019 | 0.95 | 1.22 | 0.72 |
| 2018 | 1.07 | 1.54 | 0.72 |
| 2017 | 2.02 | 4 | 1.01 |
| 2016 | 2.34 | 4 | 1.42 |
| 2015 | 1.81 | 3.11 | 1.32 |
| 2014 | 1.38 | 1.8 | 0.98 |
| 2013 | 0.95 | 1.24 | 0.76 |
| 2012 | 0.75 | 1.21 | 0.53 |
| 2011 | 2.49 | 6.35 | 0.56 |
| 2010 | 5.44 | 7.73 | 3.93 |
| 2009 | 4.25 | 6.86 | 1.46 |
| 2008 | 1.99 | 4.09 | 1.05 |
| 2007 | 2.76 | 4.07 | 1.21 |
| 2006 | 1.14 | 1.97 | 0.83 |
| 2005 | 0.78 | 0.97 | 0.59 |
| 2004 | 1.16 | 2.29 | 0.75 |