| 时间 | 平均 | 最高 | 最低 |
|---|---|---|---|
| 2025 | 0.72 | 1.52 | 0.38 |
| 2024 | 0.48 | 0.73 | 0.33 |
| 2023 | 0.69 | 0.87 | 0.56 |
| 2022 | 0.66 | 1.01 | 0.42 |
| 2021 | 0.53 | 0.68 | 0.4 |
| 2020 | 1.03 | 1.55 | 0.63 |
| 2019 | 1.02 | 1.61 | 0.61 |
| 2018 | 1.15 | 1.91 | 0.63 |
| 2017 | 1.62 | 1.85 | 1.36 |
| 2016 | 2.22 | 3.08 | 1.85 |
| 2015 | 2.45 | 4.02 | 1.52 |
| 2014 | 2.31 | 3.54 | 1.73 |
| 2013 | 2.82 | 3.69 | 1.87 |
| 2012 | 2.03 | 2.59 | 1.65 |
| 2011 | 2.53 | 3.47 | 1.86 |
| 2010 | 2.22 | 3.13 | 1.42 |
| 2009 | 2.96 | 5.13 | 1.47 |
| 2008 | 3.63 | 8.96 | 1.21 |
| 2007 | 7.35 | 10.76 | 4.37 |
| 2006 | 2.35 | 5.74 | 0.58 |
| 2005 | 0.43 | 0.59 | 0.33 |
| 2004 | 0.61 | 1.22 | 0.35 |