| 时间 | 平均 | 最高 | 最低 |
|---|---|---|---|
| 2026 | 1.86 | 2.93 | 1.34 |
| 2025 | 1.34 | 1.95 | 0.95 |
| 2024 | 1.25 | 1.84 | 0.88 |
| 2023 | 1.9 | 2.35 | 1.58 |
| 2022 | 2.9 | 4.89 | 1.93 |
| 2021 | 2.46 | 4.54 | 1.33 |
| 2020 | 1.61 | 2.17 | 1.36 |
| 2019 | 5.97 | 15.64 | 1.5 |
| 2018 | 6.88 | 11.19 | 3.59 |
| 2017 | 11.41 | 12.58 | 9.77 |
| 2016 | 11.81 | 14.13 | 8.76 |
| 2015 | 8.81 | 9.26 | 8.22 |
| 2014 | 3.68 | 6.49 | 1.7 |
| 2013 | 2.18 | 2.63 | 1.75 |
| 2012 | 2.47 | 3.14 | 1.72 |
| 2011 | 3.7 | 6.01 | 2.65 |
| 2010 | 4.23 | 6.69 | 2.99 |
| 2009 | 4.32 | 7.04 | 2.26 |
| 2008 | 3.67 | 6.14 | 1.65 |
| 2007 | 4.24 | 6.78 | 2.35 |
| 2006 | 2.4 | 3.5 | 1.61 |
| 2005 | 1.87 | 2.21 | 1.54 |