| 时间 | 平均 | 最高 | 最低 |
|---|---|---|---|
| 2025 | 1.35 | 1.81 | 0.85 |
| 2024 | 0.89 | 1.04 | 0.67 |
| 2023 | 1.17 | 1.71 | 0.91 |
| 2022 | 1.71 | 2.38 | 1.08 |
| 2021 | 1.37 | 2.21 | 1.03 |
| 2020 | 1.12 | 1.6 | 0.77 |
| 2019 | 1 | 1.29 | 0.81 |
| 2018 | 1.49 | 2.25 | 0.9 |
| 2017 | 3.01 | 4.45 | 1.98 |
| 2016 | 3.94 | 4.73 | 2.97 |
| 2015 | 4.89 | 8.21 | 3.14 |
| 2014 | 2.77 | 4.19 | 2.1 |
| 2013 | 2.19 | 2.56 | 1.63 |
| 2012 | 1.9 | 2.73 | 1.43 |
| 2011 | 3.12 | 4.85 | 2.2 |
| 2010 | 3.97 | 5.11 | 3.1 |
| 2009 | 4.11 | 5.34 | 2.68 |
| 2008 | 6.44 | 12.24 | 2.18 |
| 2007 | 13.39 | 26.18 | 8.31 |
| 2006 | 11.42 | 15.61 | 3.11 |
| 2005 | 3.82 | 14.11 | 0.44 |
| 2004 | 1.21 | 2.14 | 0.7 |