| 时间 | 平均 | 最高 | 最低 |
|---|---|---|---|
| 2025 | 1.53 | 1.63 | 1.33 |
| 2024 | 1.6 | 2.2 | 1.13 |
| 2023 | 2.39 | 2.75 | 1.98 |
| 2022 | 2.52 | 2.95 | 2.01 |
| 2021 | 2.13 | 2.94 | 1.74 |
| 2020 | 2.48 | 3.27 | 1.93 |
| 2019 | 2.9 | 4.47 | 2.35 |
| 2018 | 3.61 | 6.35 | 2.22 |
| 2017 | 5.76 | 6.69 | 4.28 |
| 2016 | 6.22 | 8 | 4.98 |
| 2015 | 10.04 | 16.45 | 4.25 |
| 2014 | 3.4 | 5.81 | 2.31 |
| 2013 | 3.12 | 4.18 | 2.42 |
| 2012 | 2.87 | 3.2 | 2.28 |
| 2011 | 4.23 | 5.28 | 2.61 |
| 2010 | 4.77 | 6.2 | 3.64 |
| 2009 | 4.35 | 6.26 | 2.19 |
| 2008 | 3.71 | 7.39 | 1.64 |
| 2007 | 4.34 | 7.08 | 1.67 |
| 2006 | 1.63 | 2.03 | 1.3 |
| 2005 | 1.53 | 2.22 | 0.95 |
| 2004 | 6.1 | 9.06 | 2.13 |
| 2003 | 6.99 | 8.46 | 5.98 |
| 2002 | 5.67 | 6.94 | 3.92 |
| 2001 | 5.4 | 6.08 | 4.73 |
| 2000 | 5.65 | 7 | 4.26 |
| 1999 | 6.05 | 8.33 | 3.79 |
| 1998 | 5.7 | 7.59 | 4.64 |