| 时间 | 平均 | 最高 | 最低 |
|---|---|---|---|
| 2026 | 1.9 | 2.96 | 1.42 |
| 2025 | 1.4 | 1.58 | 1.29 |
| 2024 | 1.33 | 1.6 | 1.12 |
| 2023 | 1.69 | 1.91 | 1.43 |
| 2022 | 1.99 | 2.45 | 1.72 |
| 2021 | 1.9 | 2.56 | 1.57 |
| 2020 | 2.44 | 3.24 | 1.83 |
| 2019 | 2.57 | 3.78 | 1.97 |
| 2018 | 3.08 | 4.39 | 2.21 |
| 2017 | 4.51 | 5.21 | 3.93 |
| 2016 | 4.73 | 5.9 | 4.18 |
| 2015 | 8.02 | 12.53 | 4.91 |
| 2014 | 6.13 | 10.02 | 4.44 |
| 2013 | 6.66 | 9.34 | 5.2 |
| 2012 | 6.25 | 7.71 | 4.94 |
| 2011 | 7.55 | 9.16 | 5.56 |
| 2010 | 7.18 | 10.6 | 4.91 |
| 2009 | 5.89 | 9.22 | 3.35 |
| 2008 | 6.84 | 14.22 | 2.85 |
| 2007 | 10.48 | 19.71 | 3.46 |
| 2006 | 3.47 | 5.36 | 2.02 |
| 2005 | 2.74 | 3.91 | 1.08 |
| 2004 | 2.13 | 3.51 | 1.44 |