| 时间 | 平均 | 最高 | 最低 |
|---|---|---|---|
| 2025 | 0 | ||
| 2024 | 1.4 | 2.22 | 0.41 |
| 2023 | 2.18 | 2.44 | 1.89 |
| 2022 | 2.57 | 3.58 | 2.08 |
| 2021 | 2.06 | 2.76 | 1.81 |
| 2020 | 2.18 | 2.91 | 1.46 |
| 2019 | 1.85 | 2.63 | 1.54 |
| 2018 | 1.97 | 2.62 | 1.51 |
| 2017 | 3.17 | 3.77 | 2.52 |
| 2016 | 3.72 | 4.5 | 3.25 |
| 2015 | 5 | 10.91 | 2.78 |
| 2014 | 2.56 | 3.41 | 1.76 |
| 2013 | 1.7 | 2.02 | 1.39 |
| 2012 | 1.51 | 1.79 | 1.27 |
| 2011 | 2.55 | 3.63 | 1.33 |
| 2010 | 3.86 | 4.81 | 3.01 |
| 2009 | 3.29 | 4.31 | 2.09 |
| 2008 | 3.35 | 5.37 | 1.59 |
| 2007 | 3.64 | 5.81 | 1.54 |
| 2006 | 1.52 | 2.62 | 0.8 |
| 2005 | 0.86 | 1.1 | 0.7 |
| 2004 | 1.56 | 2.13 | 0.93 |