| 时间 | 平均 | 最高 | 最低 |
|---|---|---|---|
| 2025 | 8.96 | 11.55 | 7.37 |
| 2024 | 4.44 | 9.54 | 1.93 |
| 2023 | 2.78 | 3.63 | 2.35 |
| 2022 | 1.94 | 2.67 | 1.01 |
| 2021 | 1.12 | 1.55 | 0.86 |
| 2020 | 1.01 | 1.52 | 0.54 |
| 2019 | 1.15 | 1.47 | 0.71 |
| 2018 | 1.22 | 1.73 | 0.69 |
| 2017 | 1.97 | 2.3 | 1.61 |
| 2016 | 2.01 | 2.36 | 1.79 |
| 2015 | 4.25 | 7.86 | 1.92 |
| 2014 | 3.87 | 5.27 | 3.15 |
| 2013 | 13.9 | 65.82 | 3.87 |
| 2012 | 17.27 | 54.79 | 9.87 |
| 2011 | 17.74 | 23.86 | 10.62 |
| 2010 | 11.32 | 22.71 | 5.09 |
| 2009 | 4.07 | 5.57 | 2.15 |
| 2008 | 3.75 | 7.92 | 1.65 |
| 2007 | 6.48 | 8.95 | 3.83 |
| 2006 | 4.26 | 4.86 | 3.59 |
| 2005 | 4.18 | 5.59 | 2.65 |
| 2004 | 5.82 | 7.72 | 4.56 |
| 2003 | 7.41 | 9.27 | 4.51 |
| 2002 | 12.73 | 14.83 | 9.06 |
| 2001 | 17.76 | 21.79 | 13.12 |
| 2000 | 21.88 | 28.06 | 17.08 |
| 1999 | 45.07 | 60.45 | 35.96 |
| 1998 | 9.52 | 18.8 | 4.57 |
| 1997 | 3.8 | 5.12 | 2.57 |