| 时间 | 平均 | 最高 | 最低 |
|---|---|---|---|
| 2025 | 1.72 | 2 | 1.44 |
| 2024 | 1.63 | 2.17 | 1.07 |
| 2023 | 1.14 | 1.52 | 0.72 |
| 2022 | 0.79 | 1.07 | 0.67 |
| 2021 | 1.26 | 1.64 | 1.03 |
| 2020 | 1.17 | 1.78 | 0.79 |
| 2019 | 0.93 | 1.16 | 0.76 |
| 2018 | 1.18 | 1.69 | 0.68 |
| 2017 | 1.44 | 1.79 | 1.23 |
| 2016 | 1.42 | 1.61 | 1.26 |
| 2015 | 1.71 | 2.12 | 1.45 |
| 2014 | 1.04 | 1.41 | 0.86 |
| 2013 | 1.07 | 1.27 | 0.89 |
| 2012 | 0.88 | 1.14 | 0.74 |
| 2011 | 0.84 | 1.15 | 0.67 |
| 2010 | 1.01 | 1.28 | 0.78 |
| 2009 | 0.91 | 1.3 | 0.54 |
| 2008 | 1.07 | 2.36 | 0.4 |
| 2007 | 1.78 | 2.62 | 1.12 |
| 2006 | 0.65 | 1.11 | 0.42 |
| 2005 | 0.46 | 0.54 | 0.31 |
| 2004 | 0.46 | 0.77 | 0.28 |