| 时间 | 平均 | 最高 | 最低 |
|---|---|---|---|
| 2025 | 0.37 | 0.39 | 0.33 |
| 2024 | 0.34 | 0.4 | 0.29 |
| 2023 | 0.47 | 0.55 | 0.37 |
| 2022 | 0.58 | 0.74 | 0.48 |
| 2021 | 0.78 | 1.11 | 0.55 |
| 2020 | 0.83 | 1.27 | 0.5 |
| 2019 | 0.63 | 0.92 | 0.47 |
| 2018 | 0.76 | 0.99 | 0.63 |
| 2017 | 1.14 | 1.45 | 0.92 |
| 2016 | 1.02 | 1.27 | 0.88 |
| 2015 | 1.4 | 2.35 | 0.9 |
| 2014 | 0.62 | 0.98 | 0.48 |
| 2013 | 0.7 | 0.9 | 0.53 |
| 2012 | 0.75 | 0.92 | 0.6 |
| 2011 | 1.26 | 1.7 | 0.73 |
| 2010 | 0.99 | 1.44 | 0.73 |
| 2009 | 0.67 | 1.06 | 0.35 |
| 2008 | 0.77 | 1.81 | 0.24 |
| 2007 | 1.52 | 2.26 | 0.9 |
| 2006 | 0.61 | 0.93 | 0.46 |
| 2005 | 0.65 | 1.02 | 0.42 |
| 2004 | 2.66 | 12.5 | 0.8 |