| 时间 | 平均 | 最高 | 最低 |
|---|---|---|---|
| 2025 | 1.93 | 2.51 | 1.66 |
| 2024 | 1.43 | 2.9 | 0.7 |
| 2023 | 1.16 | 1.26 | 1.07 |
| 2022 | 1.25 | 1.66 | 1.02 |
| 2021 | 1.15 | 1.66 | 0.91 |
| 2020 | 1.2 | 1.51 | 1.04 |
| 2019 | 1.31 | 1.69 | 1.13 |
| 2018 | 1.59 | 2.05 | 1.1 |
| 2017 | 2.76 | 4.14 | 1.91 |
| 2016 | 3.32 | 4.12 | 2.9 |
| 2015 | 4.24 | 7.49 | 2.9 |
| 2014 | 3.16 | 4.01 | 2.22 |
| 2013 | 2.05 | 3.24 | 1.55 |
| 2012 | 2.16 | 3.02 | 1.66 |
| 2011 | 3.19 | 4.52 | 1.75 |
| 2010 | 3.13 | 5.16 | 2.01 |
| 2009 | 2.07 | 3.39 | 0.76 |
| 2008 | 1.08 | 1.68 | 0.59 |
| 2007 | 1.61 | 2.56 | 1.03 |
| 2006 | 1.37 | 1.85 | 0.9 |
| 2005 | 1.03 | 1.96 | 0.55 |
| 2004 | 1.22 | 2.08 | 0.87 |