| 时间 | 平均 | 最高 | 最低 |
|---|---|---|---|
| 2025 | 1.92 | 2.17 | 1.77 |
| 2024 | 2.05 | 2.27 | 1.78 |
| 2023 | 2.13 | 2.6 | 1.84 |
| 2022 | 2.59 | 3.48 | 2.13 |
| 2021 | 2.1 | 2.55 | 1.61 |
| 2020 | 1.73 | 2.35 | 1.35 |
| 2019 | 1.61 | 2.01 | 1.42 |
| 2018 | 1.56 | 1.95 | 1.28 |
| 2017 | 2.16 | 2.62 | 1.79 |
| 2016 | 2.76 | 3.43 | 2.15 |
| 2015 | 3.41 | 5.37 | 2.23 |
| 2014 | 2.15 | 2.79 | 1.8 |
| 2013 | 2.24 | 3.15 | 1.51 |
| 2012 | 3.17 | 4.76 | 2.04 |
| 2011 | 16.22 | 137.97 | 3.93 |
| 2010 | 10.6 | 14.94 | 7.47 |
| 2009 | 5.98 | 10.88 | 2.31 |
| 2008 | 3.65 | 7.65 | 1.61 |
| 2007 | 4.28 | 7.03 | 2.17 |
| 2006 | 2.22 | 2.77 | 1.88 |
| 2005 | 2.04 | 2.91 | 1.44 |
| 2004 | 2.98 | 4.21 | 2.4 |
| 2003 | 3.75 | 4.89 | 2.44 |
| 2002 | 4.63 | 5.77 | 2.77 |
| 2001 | 5.56 | 6.84 | 3.77 |
| 2000 | 5.79 | 8.43 | 2.92 |
| 1999 | 2.7 | 3.28 | 2.17 |
| 1998 | 2.99 | 3.82 | 2.16 |
| 1997 | 3.53 | 5.24 | 2.79 |