| 时间 | 平均 | 最高 | 最低 |
|---|---|---|---|
| 2026 | 6.4 | 7.13 | 5.57 |
| 2025 | 8.89 | 11.83 | 6.16 |
| 2024 | 9.47 | 12.63 | 7.46 |
| 2023 | 9 | 11.49 | 6.7 |
| 2022 | 5.28 | 7.04 | 3.45 |
| 2021 | 5.17 | 6.37 | 4 |
| 2020 | 7.47 | 10.79 | 4.33 |
| 2019 | 1.69 | 6.71 | 0.87 |
| 2018 | 1.37 | 2.26 | 0.9 |
| 2017 | 1.27 | 1.66 | 0.87 |
| 2016 | 1.87 | 2.53 | 1.56 |
| 2015 | 2.45 | 4.12 | 1.3 |
| 2014 | 0.76 | 1.41 | 0.56 |
| 2013 | 0.53 | 0.65 | 0.39 |
| 2012 | 0.43 | 0.53 | 0.36 |
| 2011 | 0.71 | 0.98 | 0.42 |
| 2010 | 0.95 | 1.25 | 0.74 |
| 2009 | 0.75 | 1.19 | 0.42 |
| 2008 | 0.95 | 2.37 | 0.31 |
| 2007 | 2.15 | 3.05 | 1.45 |
| 2006 | 0.85 | 1.32 | 0.55 |
| 2005 | 0.62 | 0.76 | 0.46 |
| 2004 | 1.04 | 2.39 | 0.52 |