| 时间 | 平均 | 最高 | 最低 |
|---|---|---|---|
| 2026 | 1.12 | 1.18 | 0.97 |
| 2025 | 1.04 | 1.29 | 0.93 |
| 2024 | 0.85 | 1.32 | 0.6 |
| 2023 | 1.09 | 1.24 | 0.98 |
| 2022 | 1.19 | 1.45 | 1.03 |
| 2021 | 1.18 | 1.36 | 1.08 |
| 2020 | 1.23 | 1.57 | 0.96 |
| 2019 | 1.25 | 1.57 | 1.09 |
| 2018 | 1.27 | 1.55 | 1.06 |
| 2017 | 1.81 | 2.35 | 1.48 |
| 2016 | 2.02 | 2.38 | 1.64 |
| 2015 | 1.99 | 3.33 | 1.35 |
| 2014 | 1.42 | 1.68 | 1.26 |
| 2013 | 1.64 | 2.23 | 1.24 |
| 2012 | 2.74 | 5.19 | 1.58 |
| 2011 | 5.42 | 6.89 | 4.22 |
| 2010 | 5.35 | 7.7 | 3.74 |
| 2009 | 3.95 | 5.42 | 2.82 |
| 2008 | 6.03 | 11.56 | 2.45 |
| 2007 | 6.41 | 10.49 | 3.63 |
| 2006 | 2.44 | 3.84 | 1.42 |
| 2005 | 2.06 | 2.36 | 1.67 |