| 时间 | 平均 | 最高 | 最低 |
|---|---|---|---|
| 2025 | 0 | ||
| 2024 | 1.24 | 2.14 | 0.88 |
| 2023 | 2.38 | 3.58 | 1.85 |
| 2022 | 2.32 | 3.82 | 1.3 |
| 2021 | 0.99 | 1.68 | 0.62 |
| 2020 | 0.65 | 0.96 | 0.54 |
| 2019 | 0.75 | 1.15 | 0.49 |
| 2018 | 0.68 | 0.94 | 0.45 |
| 2017 | 0.88 | 1.36 | 0.6 |
| 2016 | 1.42 | 2.11 | 1.12 |
| 2015 | 2.08 | 2.97 | 1.02 |
| 2014 | 1.6 | 2.51 | 1.08 |
| 2013 | 1.37 | 1.71 | 1.17 |
| 2012 | 1.67 | 2.73 | 1 |
| 2011 | 4.31 | 7.65 | 2.08 |
| 2010 | 5.1 | 8.28 | 3.09 |
| 2009 | 2.23 | 3.68 | 1.02 |
| 2008 | 2.12 | 4.15 | 0.7 |
| 2007 | 3.33 | 4.08 | 2.59 |
| 2006 | 0.61 | 0.69 | 0.44 |
| 2005 | 0.53 | 0.68 | 0.34 |
| 2004 | 0.87 | 1.48 | 0.52 |