| 时间 | 平均 | 最高 | 最低 |
|---|---|---|---|
| 2026 | 1.67 | 1.89 | 1.46 |
| 2025 | 1.65 | 2.16 | 1.35 |
| 2024 | 1.78 | 2.15 | 1.37 |
| 2023 | 2.17 | 3.33 | 1.68 |
| 2022 | 2.32 | 3.9 | 1.08 |
| 2021 | 1.39 | 3.22 | 1.1 |
| 2020 | 1.37 | 1.69 | 1.17 |
| 2019 | 1.35 | 1.74 | 1.18 |
| 2018 | 1.68 | 2.52 | 1.17 |
| 2017 | 3.62 | 6.14 | 2.34 |
| 2016 | 5.24 | 6.22 | 3.53 |
| 2015 | 4.96 | 9.88 | 2.4 |
| 2014 | 2.22 | 2.93 | 1.79 |
| 2013 | 1.68 | 2.04 | 1.17 |
| 2012 | 1.56 | 2.42 | 1 |
| 2011 | 2.32 | 3.04 | 1.69 |
| 2010 | 2.79 | 3.7 | 2.2 |
| 2009 | 2.62 | 3.82 | 1.54 |
| 2008 | 1.8 | 3.63 | 0.7 |
| 2007 | 2.69 | 3.85 | 1.74 |
| 2006 | 1.06 | 1.9 | 0.51 |
| 2005 | 0.56 | 0.85 | 0.37 |
| 2004 | 0.76 | 1.39 | 0.44 |