| 时间 | 平均 | 最高 | 最低 |
|---|---|---|---|
| 2025 | 18.86 | 26.08 | 14.24 |
| 2024 | 12.41 | 22.51 | 9.25 |
| 2023 | 14.21 | 18.35 | 11.15 |
| 2022 | 5.27 | 18.96 | 3.03 |
| 2021 | 3.65 | 4.36 | 3.21 |
| 2020 | 3.87 | 5.1 | 2.52 |
| 2019 | 3.34 | 5.04 | 2.83 |
| 2018 | 3.46 | 4.68 | 2.75 |
| 2017 | 5.65 | 7.57 | 4.1 |
| 2016 | 5.99 | 8.64 | 3.74 |
| 2015 | 6.21 | 11.79 | 4.26 |
| 2014 | 3.26 | 4.8 | 2.14 |
| 2013 | 2.49 | 3.14 | 1.91 |
| 2012 | 2.92 | 3.82 | 2.16 |
| 2011 | 4.73 | 6.57 | 3.05 |
| 2010 | 4.7 | 6.6 | 3.26 |
| 2009 | 3.26 | 4.46 | 2.1 |
| 2008 | 3.57 | 7.12 | 1.46 |
| 2007 | 4.99 | 6.82 | 3.52 |
| 2006 | 2.81 | 3.7 | 1.75 |
| 2005 | 1.81 | 2.28 | 1.35 |
| 2004 | 3.03 | 4.25 | 2.15 |
| 2003 | 4.08 | 5.39 | 2.83 |
| 2002 | 4.71 | 5.71 | 3.69 |
| 2001 | 6.46 | 7.86 | 4.53 |
| 2000 | 5.88 | 7.22 | 4.64 |
| 1999 | 3.89 | 5.13 | 2.97 |
| 1998 | 3.92 | 4.77 | 2.98 |