| 时间 | 平均 | 最高 | 最低 |
|---|---|---|---|
| 2025 | 2.41 | 2.85 | 2.07 |
| 2024 | 2.53 | 3.36 | 1.7 |
| 2023 | 4.12 | 5.08 | 3.24 |
| 2022 | 3.23 | 4.33 | 2.48 |
| 2021 | 2.15 | 2.94 | 1.53 |
| 2020 | 1.95 | 2.91 | 1.43 |
| 2019 | 1.96 | 3.38 | 1.54 |
| 2018 | 2.02 | 3.11 | 1.34 |
| 2017 | 3.41 | 3.94 | 2.85 |
| 2016 | 2.62 | 4.73 | 1.61 |
| 2015 | 6.47 | 13.97 | 1.48 |
| 2014 | 4.74 | 6.6 | 3.53 |
| 2013 | 3.81 | 5.94 | 2.21 |
| 2012 | 2.26 | 3.08 | 1.93 |
| 2011 | 3.74 | 5.62 | 2.05 |
| 2010 | 5.05 | 6.23 | 4.14 |
| 2009 | 4.8 | 5.85 | 3.28 |
| 2008 | 4 | 6.96 | 2.26 |
| 2007 | 5.02 | 7.32 | 2.51 |
| 2006 | 2.12 | 3.41 | 1.39 |
| 2005 | 1.91 | 2.8 | 1.35 |
| 2004 | 3.76 | 6.14 | 2.29 |
| 2003 | 5.91 | 9.36 | 3.97 |
| 2002 | 9.98 | 10.82 | 8.53 |
| 2001 | 10.52 | 12.67 | 8.98 |
| 2000 | 9.31 | 10.72 | 7 |
| 1999 | 7.97 | 10.82 | 6.31 |
| 1998 | 6.32 | 9.29 | 4.26 |
| 1997 | 3.37 | 5.94 | 2.19 |