| 时间 | 平均 | 最高 | 最低 |
|---|---|---|---|
| 2024 | 0 | ||
| 2023 | 0 | ||
| 2022 | 0.34 | 0.47 | 0.1 |
| 2021 | 0.46 | 0.65 | 0.27 |
| 2020 | 0.63 | 1.09 | 0.32 |
| 2019 | 1.14 | 1.54 | 0.88 |
| 2018 | 1.6 | 2.14 | 1.24 |
| 2017 | 2.52 | 3.38 | 1.97 |
| 2016 | 15.34 | 44.19 | 3.14 |
| 2015 | 10.63 | 21.7 | 4.96 |
| 2014 | 4.72 | 5.24 | 4.02 |
| 2013 | 5.21 | 5.99 | 4.37 |
| 2012 | 7.03 | 9.53 | 4.63 |
| 2011 | 11.46 | 16.09 | 6.22 |
| 2010 | 10.17 | 13.37 | 8.14 |
| 2009 | 8.99 | 12.85 | 4.86 |
| 2008 | 11.15 | 21.81 | 3.6 |
| 2007 | 18.38 | 28.63 | 6.89 |
| 2006 | 6.42 | 8.5 | 4.85 |
| 2005 | 0 | -1.07 | |
| 2004 | 3.69 | 4.69 | 2.17 |
| 2003 | 10.05 | 12.13 | 2.28 |
| 2002 | 11.49 | 12.5 | 10.58 |
| 2001 | 10.39 | 11.65 | 8.26 |
| 2000 | 8.31 | 10.81 | 5.17 |
| 1999 | 5.51 | 6.84 | 4.31 |
| 1998 | 5.52 | 7.5 | 4.09 |