| 时间 | 平均 | 最高 | 最低 |
|---|---|---|---|
| 2025 | 8.35 | 8.97 | 8.11 |
| 2024 | 6.01 | 8.35 | 3.07 |
| 2023 | 4.71 | 10.57 | 2.08 |
| 2022 | 2.08 | 2.76 | 1.35 |
| 2021 | 1.53 | 2.51 | 0.66 |
| 2020 | 0.87 | 1.15 | 0.7 |
| 2019 | 1.13 | 1.55 | 0.91 |
| 2018 | 2.39 | 5.81 | 1.07 |
| 2017 | 7.49 | 8.98 | 5.81 |
| 2016 | 8.23 | 10.1 | 6.45 |
| 2015 | 7.39 | 9.58 | 5.77 |
| 2014 | 509.93 | 1684.6 | 35.99 |
| 2013 | 33.15 | 38.74 | 26.5 |
| 2012 | 57.03 | 111.5 | 27.67 |
| 2011 | 125.88 | 280.1 | 16.01 |
| 2010 | 13.83 | 19.37 | 9.07 |
| 2009 | 5.8 | 9.97 | 2.54 |
| 2008 | 4.75 | 9.09 | 2.07 |
| 2007 | 10.1 | 19.39 | 6.34 |
| 2006 | 25.38 | 28.97 | 20.26 |
| 2005 | 15.57 | 30.1 | 3.1 |
| 2004 | 9.35 | 16.73 | 3.55 |
| 2003 | 15.24 | 22.05 | 5.85 |
| 2002 | 7.32 | 9.07 | 4.85 |
| 2001 | 11.41 | 14.66 | 7.07 |
| 2000 | 9.63 | 14.08 | 5.11 |
| 1999 | 4.27 | 6.32 | 2.57 |
| 1998 | 2.73 | 3.51 | 1.86 |
| 1997 | 2.17 | 2.93 | 1.69 |