| 时间 | 平均 | 最高 | 最低 |
|---|---|---|---|
| 2025 | 0.96 | 1.3 | 0.53 |
| 2024 | 0.82 | 1.45 | 0.33 |
| 2023 | 2.45 | 5.45 | 1.26 |
| 2022 | 3.32 | 4.72 | 1.73 |
| 2021 | 2.92 | 4.07 | 2.15 |
| 2020 | 2.39 | 3.34 | 1.62 |
| 2019 | 2.01 | 2.6 | 1.49 |
| 2018 | 4.49 | 8.75 | 1.58 |
| 2017 | 9.15 | 10.68 | 8.12 |
| 2016 | 7.16 | 9.43 | 4.02 |
| 2015 | 4.63 | 10.67 | 2.09 |
| 2014 | 1.66 | 2.13 | 1.22 |
| 2013 | 2.11 | 3.63 | 1.16 |
| 2012 | 2.26 | 2.78 | 1.67 |
| 2011 | 2.3 | 3.02 | 1.61 |
| 2010 | 3.96 | 6.01 | 2.54 |
| 2009 | 3.15 | 5.38 | 1.48 |
| 2008 | 3.22 | 7.08 | 1.23 |
| 2007 | 8.5 | 16.84 | 2.65 |
| 2006 | 3.03 | 3.52 | 2.39 |
| 2005 | 3.51 | 4.11 | 3.04 |
| 2004 | 5.5 | 11.31 | 3.53 |