| 时间 | 平均 | 最高 | 最低 |
|---|---|---|---|
| 2025 | 0 | ||
| 2024 | 0 | ||
| 2023 | 0.14 | 0.18 | 0.07 |
| 2022 | 0.22 | 0.32 | 0.17 |
| 2021 | 0.23 | 0.34 | 0.13 |
| 2020 | 0.42 | 0.52 | 0.33 |
| 2019 | 0.57 | 0.82 | 0.42 |
| 2018 | 0.75 | 1.18 | 0.47 |
| 2017 | 0.86 | 1.09 | 0.7 |
| 2016 | 1.45 | 3.94 | 0.85 |
| 2015 | 16.11 | 79.25 | 3.98 |
| 2014 | 6.21 | 9.29 | 5.07 |
| 2013 | 5.79 | 7.79 | 4.87 |
| 2012 | 8.25 | 12.24 | 5.16 |
| 2011 | 12.27 | 18.98 | 5.28 |
| 2010 | 5.32 | 6.85 | 4.12 |
| 2009 | 5.88 | 9.04 | 2.91 |
| 2008 | 6.3 | 11.67 | 2.09 |
| 2007 | 9.27 | 12.54 | 3.68 |
| 2006 | 3.7 | 5.12 | 2.58 |
| 2005 | 2.71 | 3.33 | 2.09 |
| 2004 | 3.72 | 6.72 | 2.48 |