| 时间 | 平均 | 最高 | 最低 |
|---|---|---|---|
| 2025 | 0.22 | 0.26 | 0.19 |
| 2024 | 0.19 | 0.3 | 0.15 |
| 2023 | 0.18 | 0.28 | 0.13 |
| 2022 | 0.13 | 0.16 | 0.09 |
| 2021 | 0.59 | 2.19 | 0.1 |
| 2020 | 1.65 | 2.36 | 1.1 |
| 2019 | 1.77 | 3.12 | 1.29 |
| 2018 | 1.62 | 2.28 | 1.07 |
| 2017 | 6.18 | 13.24 | 1.99 |
| 2016 | 13.71 | 20.9 | 11.24 |
| 2015 | 23 | 42.4 | 2.88 |
| 2014 | 2.64 | 3.76 | 2.03 |
| 2013 | 2.04 | 2.4 | 1.65 |
| 2012 | 2.78 | 4.63 | 1.73 |
| 2011 | 5.46 | 7.27 | 3.26 |
| 2010 | 5.11 | 7.3 | 3.78 |
| 2009 | 3.62 | 6.1 | 1.72 |
| 2008 | 3.35 | 7.09 | 1.16 |
| 2007 | 5.27 | 8.85 | 2.7 |
| 2006 | 3.65 | 5.35 | 2.33 |
| 2005 | 3.3 | 4.57 | 2.42 |
| 2004 | 5.22 | 9.9 | 2.96 |