| 时间 | 平均 | 最高 | 最低 |
|---|---|---|---|
| 2026 | 1.77 | 1.89 | 1.55 |
| 2025 | 1.73 | 2 | 1.4 |
| 2024 | 1.46 | 1.99 | 1.14 |
| 2023 | 1.77 | 2.18 | 1.45 |
| 2022 | 1.52 | 3.2 | 1.11 |
| 2021 | 1.34 | 1.71 | 1.13 |
| 2020 | 1.94 | 2.57 | 1.38 |
| 2019 | 1.94 | 2.96 | 1.34 |
| 2018 | 1.99 | 2.63 | 1.33 |
| 2017 | 3.7 | 5.39 | 2.45 |
| 2016 | 5.27 | 7.4 | 4.63 |
| 2015 | 8 | 11.13 | 5.16 |
| 2014 | 8.12 | 14.88 | 5.67 |
| 2013 | 21.14 | 48 | 10.09 |
| 2012 | 14.31 | 22.38 | 8.29 |
| 2011 | 15.72 | 20.88 | 9.66 |
| 2010 | 22.81 | 33.92 | 15.45 |
| 2009 | 24.69 | 35.46 | 13.78 |
| 2008 | 20.95 | 35.6 | 9.55 |
| 2007 | 34.7 | 54.25 | 22.39 |
| 2006 | 21.9 | 34.44 | 11.98 |
| 2005 | 9.36 | 14.15 | 6.36 |
| 2004 | 19.56 | 41.38 | 7.87 |