| 时间 | 平均 | 最高 | 最低 |
|---|---|---|---|
| 2025 | 1.5 | 1.78 | 1.23 |
| 2024 | 1.37 | 2.55 | 1.02 |
| 2023 | 1.75 | 2.36 | 1.52 |
| 2022 | 1.37 | 2.29 | 1.14 |
| 2021 | 1.25 | 1.62 | 1.12 |
| 2020 | 1.68 | 2.03 | 1.36 |
| 2019 | 1.86 | 2.33 | 1.25 |
| 2018 | 1.59 | 2.2 | 1.12 |
| 2017 | 2.75 | 3.95 | 2.05 |
| 2016 | 3.4 | 5.18 | 2.36 |
| 2015 | 2.78 | 3.8 | 1.95 |
| 2014 | 2.42 | 2.98 | 1.79 |
| 2013 | 2.24 | 3.17 | 1.48 |
| 2012 | 1.68 | 2.33 | 1.24 |
| 2011 | 3.05 | 4.42 | 1.84 |
| 2010 | 4.03 | 4.86 | 3.32 |
| 2009 | 2.84 | 3.49 | 2.28 |
| 2008 | 3.09 | 6.06 | 1.8 |
| 2007 | 4.68 | 6.39 | 2.72 |
| 2006 | 2.75 | 4.04 | 1.93 |
| 2005 | 1.71 | 2.03 | 1.41 |
| 2004 | 2.14 | 2.7 | 1.78 |
| 2003 | 2.55 | 3.08 | 2.01 |
| 2002 | 3.79 | 4.5 | 2.64 |
| 2001 | 4.5 | 5.1 | 3.6 |
| 2000 | 3.87 | 4.73 | 2.76 |
| 1999 | 3.54 | 4.38 | 3.01 |
| 1998 | 4.24 | 5.34 | 2.71 |