| 时间 | 平均 | 最高 | 最低 |
|---|---|---|---|
| 2026 | 4.4 | 4.64 | 3.78 |
| 2025 | 4.1 | 5.16 | 3.23 |
| 2024 | 3.35 | 4.28 | 2.66 |
| 2023 | 4.1 | 4.87 | 3.58 |
| 2022 | 4.38 | 6.45 | 3.17 |
| 2021 | 4.14 | 6.33 | 3.33 |
| 2020 | 3.87 | 4.93 | 3.11 |
| 2019 | 4.05 | 5.69 | 3.18 |
| 2018 | 4.51 | 6.1 | 3.27 |
| 2017 | 8.01 | 11.58 | 5.91 |
| 2016 | 5.23 | 7.38 | 3.68 |
| 2015 | 5.69 | 8.1 | 2.92 |
| 2014 | 3.05 | 6.69 | 1.83 |
| 2013 | 1.9 | 2.89 | 1.21 |
| 2012 | 1.54 | 1.92 | 1.15 |
| 2011 | 2.53 | 3.99 | 1.53 |
| 2010 | 2.13 | 3.18 | 1.5 |
| 2009 | 2.07 | 2.67 | 1.28 |
| 2008 | 1.5 | 2.7 | 0.92 |
| 2007 | 2.83 | 4.17 | 2 |
| 2006 | 3.06 | 4.59 | 2.04 |
| 2005 | 2.5 | 3.2 | 1.7 |