| 时间 | 平均 | 最高 | 最低 |
|---|---|---|---|
| 2025 | 1.43 | 1.52 | 1.3 |
| 2024 | 1.68 | 2.14 | 1.34 |
| 2023 | 2.1 | 2.93 | 1.54 |
| 2022 | 2.23 | 3.08 | 1.47 |
| 2021 | 1.79 | 4.19 | 0.75 |
| 2020 | 0.83 | 1.11 | 0.61 |
| 2019 | 1.06 | 1.45 | 0.83 |
| 2018 | 1.21 | 1.43 | 1 |
| 2017 | 1.4 | 1.78 | 1.21 |
| 2016 | 1.36 | 2.12 | 1.06 |
| 2015 | 1.96 | 3.07 | 1.15 |
| 2014 | 1.49 | 3.02 | 1.13 |
| 2013 | 1.52 | 1.96 | 1.24 |
| 2012 | 1.91 | 2.56 | 1.35 |
| 2011 | 2.92 | 3.84 | 1.85 |
| 2010 | 4.21 | 7.34 | 2.14 |
| 2009 | 4.64 | 7.64 | 2.36 |
| 2008 | 7.93 | 23.91 | 1.75 |
| 2007 | 11.27 | 17.61 | 5.77 |
| 2006 | 6.33 | 8.96 | 4.78 |
| 2005 | 4.19 | 5.2 | 2.83 |
| 2004 | 4.81 | 7.65 | 2.93 |
| 2003 | 7.12 | 8.88 | 5.74 |
| 2002 | 6.13 | 9.05 | 2.49 |
| 2001 | 4.43 | 5.3 | 3.21 |
| 2000 | 3.74 | 4.46 | 2.9 |
| 1999 | 3.2 | 4.37 | 2.74 |
| 1998 | 5.59 | 7.18 | 4.18 |