| 时间 | 平均 | 最高 | 最低 |
|---|---|---|---|
| 2025 | 0.46 | 0.6 | 0.39 |
| 2024 | 0.44 | 0.51 | 0.38 |
| 2023 | 0.58 | 0.74 | 0.46 |
| 2022 | 0.71 | 1.07 | 0.55 |
| 2021 | 0.68 | 0.86 | 0.54 |
| 2020 | 0.7 | 1.03 | 0.57 |
| 2019 | 0.51 | 0.64 | 0.38 |
| 2018 | 0.61 | 1.06 | 0.39 |
| 2017 | 0.92 | 1.11 | 0.75 |
| 2016 | 1.07 | 1.28 | 0.9 |
| 2015 | 1.11 | 2.03 | 0.65 |
| 2014 | 0.95 | 1.12 | 0.62 |
| 2013 | 0.75 | 0.9 | 0.59 |
| 2012 | 0.99 | 1.37 | 0.65 |
| 2011 | 1.96 | 2.75 | 1.1 |
| 2010 | 2.48 | 3.42 | 1.8 |
| 2009 | 1.61 | 2.56 | 0.64 |
| 2008 | 1.76 | 4.1 | 0.47 |
| 2007 | 3.25 | 4.24 | 2.08 |
| 2006 | 3.23 | 4.73 | 2.08 |