| 时间 | 平均 | 最高 | 最低 |
|---|---|---|---|
| 2025 | 3.05 | 3.68 | 2.55 |
| 2024 | 2.34 | 4.48 | 1.19 |
| 2023 | 1.53 | 2.11 | 1.08 |
| 2022 | 1.12 | 1.54 | 0.75 |
| 2021 | 0.98 | 1.25 | 0.76 |
| 2020 | 1 | 1.48 | 0.82 |
| 2019 | 1.25 | 1.89 | 0.92 |
| 2018 | 1.76 | 2.4 | 1.12 |
| 2017 | 2.32 | 3.01 | 1.8 |
| 2016 | 2.23 | 3.28 | 1.79 |
| 2015 | 4.39 | 9.29 | 2.35 |
| 2014 | 2.03 | 2.66 | 1.52 |
| 2013 | 1.84 | 2.31 | 1.43 |
| 2012 | 1.48 | 2 | 1.09 |
| 2011 | 2.19 | 3.18 | 1.62 |
| 2010 | 2.57 | 3.4 | 1.84 |
| 2009 | 2.6 | 3.63 | 1.56 |
| 2008 | 4.03 | 9.22 | 1.43 |
| 2007 | 6.96 | 10.57 | 4.92 |
| 2006 | 3.54 | 6.26 | 2.47 |
| 2005 | 2.4 | 2.78 | 2.02 |
| 2004 | 4.45 | 9.24 | 2.12 |
| 2003 | 8.49 | 11.21 | 6.08 |
| 2002 | 8.58 | 9.66 | 6.53 |
| 2001 | 9.6 | 12.33 | 6.93 |
| 2000 | 8.23 | 10.33 | 5.63 |
| 1999 | 8.76 | 12.26 | 6.32 |
| 1998 | 7.81 | 10.39 | 6.28 |
| 1997 | 5.98 | 8.63 | 4.85 |