| 时间 | 平均 | 最高 | 最低 |
|---|---|---|---|
| 2025 | 0 | ||
| 2024 | 0 | ||
| 2023 | 0 | ||
| 2022 | 0 | ||
| 2021 | 0 | -0.04 | |
| 2020 | 5.38 | 6.41 | 4.64 |
| 2019 | 1.1 | 1.33 | 0.9 |
| 2018 | 1.6 | 3.77 | 0.59 |
| 2017 | 3.74 | 4.76 | 3.42 |
| 2016 | 3.46 | 4.53 | 2.97 |
| 2015 | 6.03 | 9.08 | 2.79 |
| 2014 | 8.34 | 27.97 | 1.89 |
| 2013 | 5.88 | 22.29 | 4.53 |
| 2012 | 5.11 | 6.2 | 4.37 |
| 2011 | 8.28 | 8.85 | 7.46 |
| 2010 | 6.62 | 9.16 | 4.52 |
| 2009 | 4.72 | 6.27 | 2.52 |
| 2008 | 3.95 | 5.64 | 1.52 |
| 2007 | 4.16 | 6.28 | 2.02 |
| 2006 | 2.38 | 2.91 | 1.98 |
| 2005 | 2.18 | 2.93 | 1.63 |
| 2004 | 3.43 | 6.64 | 1.59 |
| 2003 | 3.6 | 5.22 | 2.2 |
| 2002 | 6.39 | 7.67 | 5.48 |
| 2001 | 8.38 | 10.26 | 6.36 |
| 2000 | 7.9 | 10.43 | 5.21 |
| 1999 | 5.37 | 7.3 | 3.71 |
| 1998 | 4.6 | 6.26 | 3.06 |
| 1997 | 3.09 | 4.62 | 2.35 |