| 时间 | 平均 | 最高 | 最低 |
|---|---|---|---|
| 2025 | 0.42 | 1.31 | 0.22 |
| 2024 | 0.22 | 0.39 | 0.14 |
| 2023 | 0.21 | 0.32 | 0.17 |
| 2022 | 0.25 | 0.33 | 0.19 |
| 2021 | 0.35 | 0.45 | 0.24 |
| 2020 | 0.23 | 0.34 | 0.18 |
| 2019 | 0.29 | 0.52 | 0.22 |
| 2018 | 0.36 | 0.56 | 0.22 |
| 2017 | 1.01 | 2.03 | 0.53 |
| 2016 | 2.4 | 2.72 | 1.69 |
| 2015 | 1.76 | 2.43 | 0.86 |
| 2014 | 0.71 | 1.04 | 0.56 |
| 2013 | 0.69 | 0.8 | 0.57 |
| 2012 | 0.73 | 0.9 | 0.61 |
| 2011 | 1.21 | 1.73 | 0.7 |
| 2010 | 1.59 | 2.24 | 1.23 |
| 2009 | 1.31 | 2.5 | 0.54 |
| 2008 | 1.82 | 3.8 | 0.42 |
| 2007 | 1.83 | 3.43 | 0.69 |
| 2006 | 0.8 | 1.09 | 0.57 |
| 2005 | 1.17 | 1.74 | 0.7 |
| 2004 | 1.89 | 3.35 | 1.27 |