| 时间 | 平均 | 最高 | 最低 |
|---|---|---|---|
| 2025 | 1.23 | 1.4 | 1.09 |
| 2024 | 1.13 | 1.49 | 0.89 |
| 2023 | 1.33 | 2.05 | 1.06 |
| 2022 | 1.49 | 2.42 | 1.19 |
| 2021 | 1.25 | 1.75 | 1.05 |
| 2020 | 1.08 | 1.2 | 0.94 |
| 2019 | 1.16 | 1.49 | 0.98 |
| 2018 | 1.41 | 2.04 | 1.07 |
| 2017 | 1.9 | 2.37 | 1.64 |
| 2016 | 2.79 | 3.78 | 2.08 |
| 2015 | 3.12 | 4.55 | 1.94 |
| 2014 | 1.86 | 2.49 | 1.39 |
| 2013 | 2.17 | 2.98 | 1.59 |
| 2012 | 2.24 | 2.92 | 1.64 |
| 2011 | 3.8 | 6.07 | 2.01 |
| 2010 | 5.84 | 8.59 | 4.24 |
| 2009 | 9.7 | 13.75 | 7.99 |
| 2008 | 0 | ||
| 2007 | 0 | ||
| 2006 | 1.27 | 1.52 | 0.84 |
| 2005 | 1.46 | 2.12 | 0.89 |
| 2004 | 2.24 | 6.1 | 1.5 |
| 2003 | 2.64 | 3.08 | 2.24 |
| 2002 | 2.83 | 3.25 | 2 |
| 2001 | 4.02 | 5.31 | 2.57 |
| 2000 | 6.44 | 11.29 | 3.27 |
| 1999 | 4.24 | 5.98 | 3.34 |
| 1998 | 6 | 8.1 | 3.54 |
| 1997 | 4.61 | 6.09 | 3.33 |