| 时间 | 平均 | 最高 | 最低 |
|---|---|---|---|
| 2025 | 0.45 | 0.59 | 0.38 |
| 2024 | 0.37 | 0.49 | 0.28 |
| 2023 | 0.52 | 0.8 | 0.35 |
| 2022 | 0.51 | 0.75 | 0.4 |
| 2021 | 0.67 | 1.05 | 0.39 |
| 2020 | 0.41 | 0.53 | 0.36 |
| 2019 | 0.73 | 1.13 | 0.43 |
| 2018 | 0.85 | 1.05 | 0.67 |
| 2017 | 1.3 | 1.99 | 0.88 |
| 2016 | 0.99 | 1.43 | 0.76 |
| 2015 | 1.03 | 1.66 | 0.57 |
| 2014 | 1.86 | 4.59 | 0.66 |
| 2013 | 1.77 | 2.16 | 1.5 |
| 2012 | 1.88 | 2.55 | 1.24 |
| 2011 | 2.48 | 3.3 | 1.94 |
| 2010 | 1.87 | 3.21 | 1.18 |
| 2009 | 1.14 | 1.83 | 0.53 |
| 2008 | 0.96 | 1.81 | 0.43 |
| 2007 | 1.93 | 3.36 | 1.2 |
| 2006 | 1.15 | 1.62 | 0.72 |
| 2005 | 0.62 | 0.77 | 0.44 |
| 2004 | 0.89 | 1.66 | 0.5 |