| 时间 | 平均 | 最高 | 最低 |
|---|---|---|---|
| 2026 | 1.66 | 2.15 | 1.36 |
| 2025 | 1.65 | 1.97 | 1.39 |
| 2024 | 1.35 | 1.82 | 1.07 |
| 2023 | 1.67 | 2.1 | 1.43 |
| 2022 | 1.29 | 1.74 | 0.9 |
| 2021 | 1.42 | 1.79 | 1.19 |
| 2020 | 1.44 | 1.82 | 1.23 |
| 2019 | 1.27 | 1.78 | 0.95 |
| 2018 | 1.14 | 1.42 | 0.92 |
| 2017 | 1.46 | 1.71 | 1.24 |
| 2016 | 1.86 | 2.59 | 1.59 |
| 2015 | 3.02 | 5.73 | 1.77 |
| 2014 | 1.59 | 2.73 | 1.14 |
| 2013 | 1.44 | 2.12 | 1.1 |
| 2012 | 2.56 | 4.34 | 1.38 |
| 2011 | 2.28 | 3.1 | 1.73 |
| 2010 | 2.95 | 3.98 | 2.16 |
| 2009 | 1.31 | 2.71 | 0.55 |
| 2008 | 0.83 | 1.67 | 0.41 |
| 2007 | 1.07 | 1.61 | 0.5 |
| 2006 | 0.58 | 0.76 | 0.48 |
| 2005 | 0.7 | 1.06 | 0.53 |
| 2004 | 0.81 | 1.39 | 0.51 |