| 时间 | 平均 | 最高 | 最低 |
|---|---|---|---|
| 2025 | 0.82 | 0.97 | 0.74 |
| 2024 | 0.77 | 1.15 | 0.61 |
| 2023 | 0.85 | 1.18 | 0.65 |
| 2022 | 0.68 | 1.07 | 0.59 |
| 2021 | 0.82 | 1.16 | 0.67 |
| 2020 | 1.09 | 1.34 | 0.87 |
| 2019 | 1.4 | 1.83 | 1.19 |
| 2018 | 1.5 | 1.97 | 1.17 |
| 2017 | 150.67 | 623.81 | 1.73 |
| 2016 | 9.18 | 16.85 | 4.55 |
| 2015 | 6.33 | 10.36 | 3.95 |
| 2014 | 3.63 | 4.93 | 2.7 |
| 2013 | 3.03 | 3.65 | 2.57 |
| 2012 | 3.76 | 4.91 | 2.8 |
| 2011 | 5.83 | 8.68 | 3.05 |
| 2010 | 4.95 | 7.64 | 3.31 |
| 2009 | 4.4 | 5.73 | 2.31 |
| 2008 | 5.53 | 14.75 | 1.79 |
| 2007 | 12.74 | 22.52 | 7.58 |
| 2006 | 7.12 | 10.73 | 5.03 |
| 2005 | 6.44 | 8.32 | 4.83 |
| 2004 | 6.48 | 8.21 | 4.94 |
| 2003 | 5.62 | 6.67 | 3.96 |
| 2002 | 7.59 | 8.8 | 5.52 |
| 2001 | 9.09 | 10.82 | 7.08 |
| 2000 | 9.07 | 14.32 | 4.65 |
| 1999 | 4.39 | 5.76 | 3.16 |
| 1998 | 3.77 | 4.94 | 2.73 |
| 1997 | 3.88 | 5.61 | 2.57 |