| 时间 | 平均 | 最高 | 最低 |
|---|---|---|---|
| 2024 | 0.74 | 0.92 | 0.6 |
| 2023 | 1.58 | 2.03 | 0.88 |
| 2022 | 1.43 | 1.68 | 1.26 |
| 2021 | 1.29 | 1.66 | 1.05 |
| 2020 | 0.76 | 1.21 | 0.55 |
| 2019 | 0.74 | 1.04 | 0.61 |
| 2018 | 0.9 | 1.23 | 0.61 |
| 2017 | 1.02 | 1.2 | 0.95 |
| 2016 | 0.95 | 1.13 | 0.79 |
| 2015 | 1.14 | 1.93 | 0.65 |
| 2014 | 0.43 | 0.84 | 0.32 |
| 2013 | 0.42 | 0.5 | 0.34 |
| 2012 | 0.5 | 0.6 | 0.39 |
| 2011 | 0.83 | 1.18 | 0.49 |
| 2010 | 1.73 | 2.72 | 1.07 |
| 2009 | 0.9 | 1.51 | 0.47 |
| 2008 | 0.99 | 2.49 | 0.31 |
| 2007 | 1.29 | 2.77 | 0.5 |
| 2006 | 0.47 | 0.56 | 0.36 |
| 2005 | 0.45 | 0.55 | 0.35 |
| 2004 | 0.73 | 1.28 | 0.46 |