| 时间 | 平均 | 最高 | 最低 |
|---|---|---|---|
| 2025 | 2.98 | 3.56 | 2.56 |
| 2024 | 2.77 | 4.43 | 1.93 |
| 2023 | 2.12 | 2.61 | 1.77 |
| 2022 | 1.56 | 3.61 | 0.7 |
| 2021 | 0.66 | 1.31 | 0.35 |
| 2020 | 0.64 | 1.19 | 0.36 |
| 2019 | 0.52 | 0.8 | 0.42 |
| 2018 | 0.79 | 0.95 | 0.46 |
| 2017 | 1.44 | 2 | 0.95 |
| 2016 | 4.7 | 25.16 | 1.83 |
| 2015 | 2.63 | 6.17 | 1.61 |
| 2014 | 1.37 | 1.75 | 1.22 |
| 2013 | 1.27 | 1.5 | 1.11 |
| 2012 | 1.89 | 2.7 | 1.08 |
| 2011 | 2.71 | 3.46 | 1.83 |
| 2010 | 3.21 | 3.83 | 2.5 |
| 2009 | 2.37 | 3.05 | 1.47 |
| 2008 | 2.24 | 3.8 | 1.14 |
| 2007 | 3.06 | 4.59 | 1.64 |
| 2006 | 1.36 | 1.69 | 1.05 |
| 2005 | 1.1 | 1.38 | 0.86 |
| 2004 | 1.63 | 2.2 | 1.27 |
| 2003 | 2.06 | 2.46 | 1.6 |
| 2002 | 2.79 | 3.14 | 2.13 |
| 2001 | 3.83 | 4.77 | 2.72 |
| 2000 | 3.92 | 4.76 | 2.97 |
| 1999 | 3.14 | 5.24 | 1.72 |
| 1998 | 2.23 | 2.88 | 1.8 |
| 1997 | 2.77 | 4.66 | 1.74 |