| 时间 | 平均 | 最高 | 最低 |
|---|---|---|---|
| 2025 | 1.54 | 1.68 | 1.31 |
| 2024 | 1.28 | 1.73 | 0.73 |
| 2023 | 0.88 | 1.04 | 0.7 |
| 2022 | 0.75 | 0.87 | 0.66 |
| 2021 | 0.91 | 1.16 | 0.75 |
| 2020 | 1.07 | 1.22 | 0.92 |
| 2019 | 1.15 | 1.44 | 0.85 |
| 2018 | 1.18 | 1.68 | 0.84 |
| 2017 | 2.2 | 2.74 | 1.6 |
| 2016 | 2.66 | 3.27 | 2.35 |
| 2015 | 3.66 | 5.61 | 2.41 |
| 2014 | 2.52 | 3.27 | 1.96 |
| 2013 | 1.71 | 2.79 | 0.95 |
| 2012 | 0.88 | 1 | 0.66 |
| 2011 | 0.87 | 1.07 | 0.64 |
| 2010 | 0.89 | 1.21 | 0.64 |
| 2009 | 0.63 | 1.1 | 0.36 |
| 2008 | 0.64 | 1.27 | 0.21 |
| 2007 | 0.97 | 1.48 | 0.48 |
| 2006 | 0.35 | 0.5 | 0.17 |
| 2005 | 0.24 | 0.33 | 0.17 |
| 2004 | 0.5 | 0.96 | 0.26 |