| 时间 | 平均 | 最高 | 最低 |
|---|---|---|---|
| 2026 | 2.17 | 2.24 | 2.05 |
| 2025 | 2.01 | 2.32 | 1.71 |
| 2024 | 1.53 | 2.02 | 1.28 |
| 2023 | 1.62 | 2.09 | 1.24 |
| 2022 | 1.43 | 1.82 | 1.21 |
| 2021 | 1.65 | 1.94 | 1.4 |
| 2020 | 2.04 | 2.67 | 1.72 |
| 2019 | 2.32 | 3.25 | 1.65 |
| 2018 | 2.21 | 2.9 | 1.45 |
| 2017 | 2.46 | 2.9 | 2.23 |
| 2016 | 2.86 | 3.78 | 2.34 |
| 2015 | 4.5 | 6.56 | 2.46 |
| 2014 | 4.59 | 6.24 | 3.45 |
| 2013 | 2.84 | 7.74 | 1.27 |
| 2012 | 1.07 | 1.39 | 0.92 |
| 2011 | 1.46 | 2.03 | 1 |
| 2010 | 1.76 | 2.45 | 1.14 |
| 2009 | 4.62 | 14.28 | 1.2 |
| 2008 | 8.29 | 16.41 | 3.3 |
| 2007 | 19.75 | 31.58 | 13.57 |
| 2006 | 11.34 | 15.51 | 7.62 |
| 2005 | 6.62 | 9.97 | 4.55 |
| 2004 | 9.37 | 17.99 | 5.43 |