| 时间 | 平均 | 最高 | 最低 |
|---|---|---|---|
| 2025 | 0.89 | 0.98 | 0.79 |
| 2024 | 0.89 | 1.11 | 0.71 |
| 2023 | 1.67 | 3.16 | 1.04 |
| 2022 | 2.76 | 3.93 | 2.08 |
| 2021 | 2.87 | 4.36 | 2.09 |
| 2020 | 2.14 | 3.32 | 1.32 |
| 2019 | 1.62 | 2.5 | 1.3 |
| 2018 | 2.31 | 3.68 | 1.37 |
| 2017 | 3.21 | 4.79 | 2.06 |
| 2016 | 2.05 | 3.2 | 1.42 |
| 2015 | 1.4 | 2.34 | 0.87 |
| 2014 | 0.89 | 1.11 | 0.71 |
| 2013 | 1.04 | 1.49 | 0.79 |
| 2012 | 1.08 | 1.79 | 0.7 |
| 2011 | 1.18 | 1.6 | 0.74 |
| 2010 | 2.08 | 3.59 | 1.36 |
| 2009 | 2.31 | 4.03 | 1.07 |
| 2008 | 2.96 | 5.69 | 0.81 |
| 2007 | 2.65 | 4.86 | 1.03 |
| 2006 | 1.16 | 1.58 | 0.92 |
| 2005 | 0.87 | 1.12 | 0.57 |
| 2004 | 1.11 | 1.86 | 0.7 |