| 时间 | 平均 | 最高 | 最低 |
|---|---|---|---|
| 2025 | 0.51 | 0.54 | 0.46 |
| 2024 | 0.49 | 0.53 | 0.44 |
| 2023 | 0.62 | 0.76 | 0.48 |
| 2022 | 0.56 | 0.65 | 0.49 |
| 2021 | 0.73 | 0.96 | 0.54 |
| 2020 | 0.78 | 0.95 | 0.66 |
| 2019 | 0.84 | 1.05 | 0.66 |
| 2018 | 1.09 | 1.62 | 0.73 |
| 2017 | 1.38 | 1.84 | 1.06 |
| 2016 | 1.21 | 1.43 | 1.06 |
| 2015 | 2 | 2.88 | 1.33 |
| 2014 | 1.56 | 2.26 | 0.59 |
| 2013 | 0.73 | 0.99 | 0.58 |
| 2012 | 0.89 | 1.3 | 0.6 |
| 2011 | 1.91 | 2.57 | 1.04 |
| 2010 | 2.23 | 3.34 | 1.63 |
| 2009 | 1.7 | 3.14 | 0.27 |
| 2008 | 0.69 | 1.76 | 0.19 |
| 2007 | 0.92 | 1.64 | 0.3 |
| 2006 | 0.26 | 0.35 | 0.19 |
| 2005 | 0.14 | 0.22 | 0.06 |
| 2004 | 0.17 | 0.34 | 0.09 |