| 时间 | 平均 | 最高 | 最低 |
|---|---|---|---|
| 2025 | 2.1 | 2.55 | 1.85 |
| 2024 | 1.42 | 2.98 | 1.04 |
| 2023 | 1.7 | 2.07 | 1.36 |
| 2022 | 0.74 | 1.54 | 0.52 |
| 2021 | 0.6 | 0.71 | 0.55 |
| 2020 | 0.68 | 0.84 | 0.5 |
| 2019 | 0.71 | 1.18 | 0.47 |
| 2018 | 1 | 1.51 | 0.55 |
| 2017 | 2.02 | 2.53 | 1.24 |
| 2016 | 2.52 | 3.21 | 2.21 |
| 2015 | 3.46 | 5.18 | 2 |
| 2014 | 2.66 | 3.68 | 1.8 |
| 2013 | 3.44 | 5.49 | 2.35 |
| 2012 | 2.52 | 3.2 | 2.02 |
| 2011 | 4.07 | 6.69 | 3.2 |
| 2010 | 5.13 | 6.69 | 3.79 |
| 2009 | 2.75 | 4.47 | 1.23 |
| 2008 | 2.98 | 7.46 | 0.98 |
| 2007 | 6.33 | 10.43 | 4.03 |
| 2006 | 3.41 | 5.62 | 1.1 |
| 2005 | 2.91 | 8.42 | 1.14 |
| 2004 | 9.42 | 12.76 | 7.49 |