| 时间 | 平均 | 最高 | 最低 |
|---|---|---|---|
| 2025 | 0 | ||
| 2024 | 0 | ||
| 2023 | 0 | ||
| 2022 | 0 | ||
| 2021 | 0 | ||
| 2020 | 0 | ||
| 2019 | 0 | -5.97 | |
| 2018 | 2.96 | 2.99 | 2.95 |
| 2017 | 1.64 | 1.78 | 1.52 |
| 2016 | 1.51 | 2.07 | 1.12 |
| 2015 | 1.56 | 2.44 | 1.04 |
| 2014 | 0.96 | 1.48 | 0.63 |
| 2013 | 0.66 | 0.84 | 0.58 |
| 2012 | 0.62 | 0.84 | 0.45 |
| 2011 | 1.21 | 2.13 | 0.55 |
| 2010 | 1.91 | 2.63 | 1.56 |
| 2009 | 2.23 | 3.4 | 1.34 |
| 2008 | 2.7 | 5.59 | 0.68 |
| 2007 | 5.04 | 8.71 | 1.83 |
| 2006 | 1.21 | 2.35 | 0.54 |
| 2005 | 0.59 | 0.72 | 0.51 |
| 2004 | 0.69 | 1.06 | 0.44 |
| 2003 | 0.79 | 0.96 | 0.61 |
| 2002 | 1.04 | 1.52 | 0.73 |
| 2001 | 1.26 | 1.98 | 0.98 |