| 时间 | 平均 | 最高 | 最低 |
|---|---|---|---|
| 2026 | 1.76 | 2.32 | 1.5 |
| 2025 | 1.44 | 1.74 | 1.23 |
| 2024 | 1 | 1.46 | 0.69 |
| 2023 | 0.97 | 1.09 | 0.85 |
| 2022 | 1.19 | 1.6 | 0.97 |
| 2021 | 1.32 | 2.28 | 1.1 |
| 2020 | 1.23 | 1.47 | 1.09 |
| 2019 | 1.75 | 2.81 | 1.34 |
| 2018 | 1.73 | 2.8 | 0.9 |
| 2017 | 2.3 | 4.24 | 0.86 |
| 2016 | 2.04 | 5.47 | 0.73 |
| 2015 | 1.09 | 1.61 | 0.62 |
| 2014 | 0.78 | 1.24 | 0.57 |
| 2013 | 0.68 | 0.85 | 0.53 |
| 2012 | 0.87 | 1.17 | 0.59 |
| 2011 | 1.11 | 1.4 | 0.9 |
| 2010 | 1.21 | 1.57 | 0.95 |
| 2009 | 1.12 | 1.39 | 0.76 |
| 2008 | 1.57 | 2.69 | 0.55 |
| 2007 | 1.89 | 2.64 | 1.13 |
| 2006 | 1.19 | 1.71 | 0.9 |
| 2005 | 1.24 | 1.62 | 0.87 |
| 2004 | 1.2 | 2.01 | 0.89 |