| 时间 | 平均 | 最高 | 最低 |
|---|---|---|---|
| 2025 | 1.06 | 1.27 | 0.88 |
| 2024 | 0.93 | 1.08 | 0.81 |
| 2023 | 1.16 | 1.43 | 1 |
| 2022 | 1.55 | 1.97 | 1.32 |
| 2021 | 1.53 | 1.91 | 1.29 |
| 2020 | 1.7 | 2.19 | 1.35 |
| 2019 | 1.75 | 2.43 | 1.29 |
| 2018 | 5.72 | 16.49 | 1.12 |
| 2017 | 6.92 | 16.43 | 4.72 |
| 2016 | 6.05 | 9.04 | 4.08 |
| 2015 | 6.08 | 13.01 | 3.09 |
| 2014 | 2.73 | 3.91 | 2.01 |
| 2013 | 2 | 2.52 | 1.59 |
| 2012 | 2.01 | 2.95 | 1.3 |
| 2011 | 3.32 | 4.79 | 2.25 |
| 2010 | 2.52 | 3.05 | 1.91 |
| 2009 | 1.81 | 2.92 | 0.94 |
| 2008 | 1.44 | 2.63 | 0.66 |
| 2007 | 1.9 | 2.52 | 1.28 |
| 2006 | 1.26 | 1.5 | 1.04 |
| 2005 | 1.67 | 2.24 | 1.13 |
| 2004 | 2.19 | 2.37 | 1.99 |