| 时间 | 平均 | 最高 | 最低 |
|---|---|---|---|
| 2026 | 0.44 | 0.53 | 0.36 |
| 2025 | 0.36 | 0.43 | 0.31 |
| 2024 | 0.32 | 0.37 | 0.27 |
| 2023 | 0.35 | 0.38 | 0.33 |
| 2022 | 0.4 | 0.5 | 0.32 |
| 2021 | 0.6 | 0.92 | 0.43 |
| 2020 | 0.36 | 0.52 | 0.26 |
| 2019 | 0.39 | 0.58 | 0.32 |
| 2018 | 0.46 | 0.64 | 0.37 |
| 2017 | 0.52 | 0.65 | 0.37 |
| 2016 | 1.03 | 1.89 | 0.64 |
| 2015 | 1.44 | 2.58 | 0.83 |
| 2014 | 0.75 | 0.93 | 0.56 |
| 2013 | 0.68 | 0.82 | 0.58 |
| 2012 | 0.74 | 0.95 | 0.54 |
| 2011 | 1.38 | 1.9 | 0.76 |
| 2010 | 1.92 | 2.31 | 1.27 |
| 2009 | 1.27 | 2.72 | 0.4 |
| 2008 | 0.78 | 1.41 | 0.28 |
| 2007 | 1.29 | 1.96 | 0.85 |
| 2006 | 1.16 | 1.56 | 0.81 |
| 2005 | 0.83 | 1.41 | 0.46 |
| 2004 | 0.91 | 1.59 | 0.6 |