| 时间 | 平均 | 最高 | 最低 |
|---|---|---|---|
| 2025 | 5.81 | 6.18 | 5.13 |
| 2024 | 5.4 | 10.13 | 2.44 |
| 2023 | 9.84 | 11.4 | 8.01 |
| 2022 | 9.8 | 12.67 | 7.76 |
| 2021 | 7.41 | 9.09 | 6.65 |
| 2020 | 8.83 | 12.18 | 7.5 |
| 2019 | 12.55 | 20.08 | 9.08 |
| 2018 | 10.29 | 23.62 | 5.79 |
| 2017 | 17.1 | 29 | 10.24 |
| 2016 | 27.23 | 41.15 | 20.39 |
| 2015 | 24.18 | 46.08 | 10.95 |
| 2014 | 9.44 | 17.81 | 6.79 |
| 2013 | 8.54 | 12.5 | 7.47 |
| 2012 | 0 | ||
| 2011 | 0 | ||
| 2010 | 0 | ||
| 2009 | 0 | ||
| 2008 | 0 | ||
| 2007 | 0 | ||
| 2006 | 0 | -0.93 | |
| 2005 | 2.37 | 2.72 | 1.65 |
| 2004 | 3.9 | 5.59 | 2.52 |
| 2003 | 5.61 | 6.81 | 4.18 |
| 2002 | 6.28 | 6.9 | 4.62 |
| 2001 | 8.99 | 11.14 | 6.21 |
| 2000 | 9.13 | 12.16 | 5.43 |
| 1999 | 5.98 | 9.36 | 3.04 |
| 1998 | 7.07 | 8.78 | 5.25 |
| 1997 | 6.75 | 8.91 | 4.33 |