| 时间 | 平均 | 最高 | 最低 |
|---|---|---|---|
| 2025 | 1.25 | 1.4 | 1.15 |
| 2024 | 1.88 | 2.68 | 1.29 |
| 2023 | 0.62 | 2.79 | 0.23 |
| 2022 | 0.29 | 0.36 | 0.25 |
| 2021 | 0.38 | 0.47 | 0.3 |
| 2020 | 0.37 | 0.47 | 0.31 |
| 2019 | 0.49 | 0.6 | 0.39 |
| 2018 | 0.66 | 0.96 | 0.43 |
| 2017 | 0.91 | 1.36 | 0.73 |
| 2016 | 0.62 | 0.85 | 0.51 |
| 2015 | 0.71 | 1.38 | 0.47 |
| 2014 | 0.43 | 0.67 | 0.33 |
| 2013 | 0.47 | 0.58 | 0.4 |
| 2012 | 0.56 | 0.74 | 0.43 |
| 2011 | 0.94 | 1.2 | 0.58 |
| 2010 | 1.14 | 1.67 | 0.76 |
| 2009 | 1.11 | 1.8 | 0.44 |
| 2008 | 1.38 | 3.56 | 0.33 |
| 2007 | 1.99 | 3.9 | 1.11 |
| 2006 | 1.04 | 1.43 | 0.71 |
| 2005 | 0.8 | 1.13 | 0.63 |
| 2004 | 1.21 | 2.32 | 0.79 |