| 时间 | 平均 | 最高 | 最低 |
|---|---|---|---|
| 2026 | 1.49 | 2.02 | 1.26 |
| 2025 | 1.24 | 1.36 | 1.13 |
| 2024 | 1.19 | 1.45 | 0.97 |
| 2023 | 1.39 | 1.68 | 1.15 |
| 2022 | 1.38 | 1.83 | 1.06 |
| 2021 | 2.42 | 3.96 | 1.59 |
| 2020 | 1.62 | 2.18 | 1.42 |
| 2019 | 1.8 | 2.47 | 1.49 |
| 2018 | 2.04 | 2.57 | 1.47 |
| 2017 | 3.15 | 4.4 | 2.29 |
| 2016 | 4.64 | 5.79 | 3.73 |
| 2015 | 8.06 | 13.72 | 3.66 |
| 2014 | 7.73 | 9.02 | 6.25 |
| 2013 | 10.15 | 16.51 | 3.75 |
| 2012 | 3.69 | 6.57 | 2.74 |
| 2011 | 4.73 | 6.24 | 3.83 |
| 2010 | 4.94 | 7.28 | 3.56 |
| 2009 | 2.95 | 4.66 | 1.54 |
| 2008 | 2.79 | 5.32 | 1.12 |
| 2007 | 3.09 | 5.04 | 1.79 |
| 2006 | 1.87 | 2.48 | 1.4 |
| 2005 | 1.6 | 2.02 | 1.25 |
| 2004 | 2.25 | 2.94 | 1.76 |