| 时间 | 平均 | 最高 | 最低 |
|---|---|---|---|
| 2025 | 0.76 | 0.94 | 0.61 |
| 2024 | 0.64 | 0.95 | 0.48 |
| 2023 | 0.98 | 1.66 | 0.64 |
| 2022 | 1.06 | 1.75 | 0.63 |
| 2021 | 1.01 | 1.27 | 0.8 |
| 2020 | 1.25 | 1.65 | 0.94 |
| 2019 | 1.17 | 1.55 | 0.88 |
| 2018 | 1.03 | 1.31 | 0.78 |
| 2017 | 1.48 | 2.1 | 1.09 |
| 2016 | 2.25 | 2.73 | 1.8 |
| 2015 | 3.36 | 7.03 | 1.66 |
| 2014 | 1.28 | 2.23 | 0.91 |
| 2013 | 0.94 | 1.26 | 0.75 |
| 2012 | 0.76 | 0.86 | 0.59 |
| 2011 | 1.09 | 1.6 | 0.63 |
| 2010 | 1.58 | 2.13 | 1.12 |
| 2009 | 1.33 | 2.02 | 0.74 |
| 2008 | 1.17 | 1.94 | 0.52 |
| 2007 | 0.98 | 1.36 | 0.62 |
| 2006 | 0.64 | 0.92 | 0.5 |
| 2005 | 0.54 | 0.75 | 0.42 |
| 2004 | 1.1 | 2.34 | 0.66 |