| 时间 | 平均 | 最高 | 最低 |
|---|---|---|---|
| 2025 | 2.11 | 2.49 | 1.8 |
| 2024 | 1.85 | 2.31 | 1.4 |
| 2023 | 2.53 | 3.62 | 1.88 |
| 2022 | 3.58 | 5.46 | 2.68 |
| 2021 | 2.39 | 4.76 | 1.42 |
| 2020 | 1.59 | 2.12 | 1.15 |
| 2019 | 1.39 | 1.81 | 1.13 |
| 2018 | 1.48 | 1.98 | 1.09 |
| 2017 | 3.06 | 6.12 | 1.51 |
| 2016 | 3.26 | 4.78 | 2.58 |
| 2015 | 4.07 | 4.77 | 2.57 |
| 2014 | 3.17 | 4.68 | 2.23 |
| 2013 | 7.56 | 24.98 | 3.23 |
| 2012 | 6.01 | 8.38 | 3.55 |
| 2011 | 7.26 | 9.6 | 3.81 |
| 2010 | 10.11 | 13.59 | 7.54 |
| 2009 | 5.25 | 10.54 | 1.46 |
| 2008 | 2.52 | 4.85 | 1.19 |
| 2007 | 3.73 | 5.59 | 2.04 |
| 2006 | 2.11 | 2.58 | 1.74 |
| 2005 | 2.6 | 3.34 | 1.78 |
| 2004 | 3.3 | 6.01 | 2.31 |
| 2003 | 4.86 | 5.34 | 4.33 |
| 2002 | 5.82 | 8.35 | 4.48 |
| 2001 | 10.89 | 13.31 | 8.11 |
| 2000 | 11.68 | 15.56 | 6.93 |
| 1999 | 5.97 | 8.2 | 4.02 |
| 1998 | 7.13 | 10.42 | 5.5 |
| 1997 | 4.5 | 8.1 | 2.29 |