| 时间 | 平均 | 最高 | 最低 |
|---|---|---|---|
| 2025 | 1.33 | 1.71 | 1.19 |
| 2024 | 1.12 | 2.39 | 0.83 |
| 2023 | 1.31 | 1.74 | 1.2 |
| 2022 | 1.33 | 1.87 | 1.08 |
| 2021 | 1.41 | 2.42 | 0.96 |
| 2020 | 1.12 | 1.85 | 0.9 |
| 2019 | 1.17 | 1.48 | 1 |
| 2018 | 1.27 | 1.48 | 1.05 |
| 2017 | 1.66 | 2 | 1.45 |
| 2016 | 2.15 | 2.55 | 1.77 |
| 2015 | 3.33 | 6.6 | 1.55 |
| 2014 | 2.19 | 3.19 | 1.72 |
| 2013 | 1.95 | 2.62 | 1.48 |
| 2012 | 2.63 | 3.71 | 1.64 |
| 2011 | 4.72 | 6.34 | 3.28 |
| 2010 | 5.81 | 7.62 | 4.58 |
| 2009 | 3.94 | 5.65 | 2.53 |
| 2008 | 4.77 | 7.91 | 2.35 |
| 2007 | 5.97 | 7.41 | 4.35 |
| 2006 | 3.5 | 5.06 | 2.23 |
| 2005 | 1.89 | 2.4 | 1.26 |
| 2004 | 2.71 | 3.94 | 1.5 |
| 2003 | 3.04 | 3.25 | 2.87 |