| 时间 | 平均 | 最高 | 最低 |
|---|---|---|---|
| 2025 | 2.11 | 2.25 | 1.8 |
| 2024 | 2.17 | 2.71 | 1.56 |
| 2023 | 2.65 | 3.22 | 2.06 |
| 2022 | 3.59 | 5.47 | 2.47 |
| 2021 | 4.34 | 6.01 | 3.33 |
| 2020 | 3.3 | 4.83 | 2.36 |
| 2019 | 2.97 | 3.52 | 2.61 |
| 2018 | 3.08 | 3.93 | 2.51 |
| 2017 | 4.8 | 6.23 | 3.42 |
| 2016 | 6.61 | 8.62 | 5.48 |
| 2015 | 7.06 | 11.23 | 4.23 |
| 2014 | 3.6 | 5.08 | 2.87 |
| 2013 | 4.03 | 5.3 | 2.6 |
| 2012 | 3.57 | 4.64 | 2.54 |
| 2011 | 5.23 | 7.13 | 3.89 |
| 2010 | 4.64 | 8.93 | 1.93 |
| 2009 | 6.6 | 9.87 | 1.74 |
| 2008 | 4.85 | 8.72 | 2.32 |
| 2007 | 5.8 | 9.98 | 2.68 |
| 2006 | 2.91 | 4.61 | 1.62 |
| 2005 | 1.7 | 2.54 | 1.12 |
| 2004 | 2.1 | 3.01 | 1.51 |
| 2003 | 2.47 | 3.13 | 1.9 |
| 2002 | 3.12 | 4.04 | 1.24 |
| 2001 | 2.79 | 3.26 | 1.96 |
| 2000 | 2.4 | 3.08 | 1.64 |
| 1999 | 2.1 | 2.83 | 1.58 |
| 1998 | 3.03 | 4.13 | 1.61 |