| 时间 | 平均 | 最高 | 最低 |
|---|---|---|---|
| 2025 | 0.59 | 0.74 | 0.51 |
| 2024 | 0.55 | 0.62 | 0.45 |
| 2023 | 0.57 | 0.69 | 0.42 |
| 2022 | 0.43 | 0.56 | 0.33 |
| 2021 | 0.41 | 0.47 | 0.34 |
| 2020 | 0.42 | 0.51 | 0.36 |
| 2019 | 0.57 | 0.77 | 0.45 |
| 2018 | 0.92 | 1.5 | 0.6 |
| 2017 | 1.81 | 2.56 | 1.18 |
| 2016 | 1.46 | 1.82 | 1.14 |
| 2015 | 2.28 | 3.89 | 1.33 |
| 2014 | 1.81 | 2.55 | 1.53 |
| 2013 | 1.91 | 2.58 | 1.49 |
| 2012 | 3.28 | 4.64 | 1.81 |
| 2011 | 6.33 | 9.16 | 4.37 |
| 2010 | 7.03 | 9.51 | 5.65 |
| 2009 | 4.85 | 6.22 | 3.89 |
| 2008 | 5.1 | 10.16 | 2.96 |
| 2007 | 10.55 | 14.72 | 7.18 |
| 2006 | 7.21 | 9.55 | 5.5 |
| 2005 | 5.2 | 6.98 | 3.36 |
| 2004 | 4.47 | 6.46 | 3.4 |