| 时间 | 平均 | 最高 | 最低 |
|---|---|---|---|
| 2025 | 0 | ||
| 2024 | 0 | ||
| 2023 | 0 | -0.05 | |
| 2022 | 2.75 | 5.49 | 0.59 |
| 2021 | 0.59 | 1.02 | 0.34 |
| 2020 | 0.92 | 1.33 | 0.66 |
| 2019 | 1.19 | 1.6 | 1.04 |
| 2018 | 1.37 | 2.59 | 0.8 |
| 2017 | 1.88 | 2.26 | 1.59 |
| 2016 | 2.14 | 3.41 | 1.75 |
| 2015 | 8.36 | 52.39 | 3.04 |
| 2014 | 4.04 | 6.14 | 3.36 |
| 2013 | 3.82 | 4.99 | 3.26 |
| 2012 | 4.93 | 6.98 | 3.31 |
| 2011 | 7.43 | 11.57 | 3.4 |
| 2010 | 3.36 | 4.17 | 2.64 |
| 2009 | 3.25 | 4.92 | 1.4 |
| 2008 | 2.81 | 4.93 | 1 |
| 2007 | 3.38 | 4.92 | 1.02 |
| 2006 | 1.03 | 1.42 | 0.73 |
| 2005 | 0.84 | 1.14 | 0.62 |
| 2004 | 1.35 | 1.83 | 1.03 |
| 2003 | 1.94 | 2.84 | 1.34 |
| 2002 | 2.88 | 3.05 | 2.71 |