| 时间 | 平均 | 最高 | 最低 |
|---|---|---|---|
| 2026 | 0 | -1 | |
| 2025 | 10.5 | 21.69 | 4.14 |
| 2024 | 2.56 | 7.32 | 1.38 |
| 2023 | 2.25 | 4.29 | 1.45 |
| 2022 | 1.81 | 2.32 | 1.31 |
| 2021 | 0.79 | 1.42 | 0.52 |
| 2020 | 0.78 | 0.95 | 0.63 |
| 2019 | 1.05 | 1.55 | 0.75 |
| 2018 | 2.28 | 2.95 | 1.02 |
| 2017 | 2.83 | 3.29 | 2.49 |
| 2016 | 2.97 | 3.73 | 2.69 |
| 2015 | 3.57 | 8.42 | 1.62 |
| 2014 | 1.74 | 2.29 | 1.28 |
| 2013 | 1.95 | 2.07 | 1.71 |
| 2012 | 128.88 | 158.12 | 112.14 |
| 2011 | 84.71 | 151.65 | 13.74 |
| 2010 | 11.89 | 17.66 | 8.83 |
| 2009 | 7.73 | 10.84 | 4.89 |
| 2008 | 8.56 | 22.23 | 2.82 |
| 2007 | 12.04 | 21.58 | 3.3 |
| 2006 | 3.6 | 4.5 | 3.05 |
| 2005 | 2.48 | 4.34 | 1.31 |
| 2004 | 3.09 | 4.59 | 2.37 |
| 2003 | 3.94 | 5.07 | 2.65 |
| 2002 | 4.63 | 6.22 | 2.17 |
| 2001 | 4.15 | 5.15 | 2.97 |
| 2000 | 4.46 | 5.31 | 2.99 |
| 1999 | 3.11 | 4 | 2.5 |
| 1998 | 2.66 | 3.37 | 2.06 |
| 1997 | 3.19 | 4.56 | 2.2 |