| 时间 | 平均 | 最高 | 最低 |
|---|---|---|---|
| 2025 | 2.78 | 3.16 | 2.41 |
| 2024 | 2.31 | 3.08 | 1.69 |
| 2023 | 2.38 | 2.74 | 2.16 |
| 2022 | 2.66 | 3.74 | 2.12 |
| 2021 | 2.7 | 3.43 | 2.13 |
| 2020 | 3.08 | 4.73 | 2.15 |
| 2019 | 2.81 | 3.41 | 2.23 |
| 2018 | 4.92 | 7.37 | 2.35 |
| 2017 | 6.47 | 7.37 | 4.97 |
| 2016 | 9.32 | 16.37 | 6.7 |
| 2015 | 25.43 | 58.65 | 12.97 |
| 2014 | 33.1 | 67.79 | 15.64 |
| 2013 | 61.05 | 90 | 36.42 |
| 2012 | 43.97 | 58.98 | 29.94 |
| 2011 | 46.17 | 64.23 | 22.42 |
| 2010 | 22.03 | 28.08 | 14.97 |
| 2009 | 17.41 | 23.96 | 10.77 |
| 2008 | 20.23 | 36.3 | 8.83 |
| 2007 | 26.43 | 42.46 | 8.45 |
| 2006 | 8.13 | 14.07 | 2.64 |
| 2005 | 3.41 | 4.24 | 2.42 |
| 2004 | 6.18 | 13.33 | 3.26 |
| 2003 | 16.03 | 21.12 | 12.76 |
| 2002 | 11.17 | 13.32 | 8.75 |
| 2001 | 8.99 | 10.56 | 6.56 |
| 2000 | 6.98 | 9.76 | 4.51 |
| 1999 | 4.3 | 5.08 | 3.39 |
| 1998 | 5.52 | 8.5 | 4.01 |
| 1997 | 4.43 | 5.9 | 3.03 |