| 时间 | 平均 | 最高 | 最低 |
|---|---|---|---|
| 2025 | 1.36 | 1.47 | 1.27 |
| 2024 | 1.42 | 1.73 | 1.24 |
| 2023 | 1.82 | 2.39 | 1.46 |
| 2022 | 2.04 | 4.12 | 1.07 |
| 2021 | 1.3 | 1.58 | 1.11 |
| 2020 | 1.71 | 2.05 | 1.51 |
| 2019 | 1.69 | 2.13 | 1.48 |
| 2018 | 2.55 | 3.68 | 1.59 |
| 2017 | 3.59 | 3.99 | 3.09 |
| 2016 | 2.91 | 3.81 | 2.21 |
| 2015 | 3.55 | 4.91 | 2.53 |
| 2014 | 2.9 | 3.7 | 2.23 |
| 2013 | 3.45 | 4.88 | 2.32 |
| 2012 | 3.64 | 4.24 | 2.95 |
| 2011 | 4.45 | 5.82 | 3.09 |
| 2010 | 3.8 | 5.56 | 2.46 |
| 2009 | 3.39 | 6.01 | 2.18 |
| 2008 | 3.57 | 8.98 | 1.46 |
| 2007 | 5.02 | 8.43 | 2.63 |
| 2006 | 2.26 | 3.16 | 1.84 |
| 2005 | 1.82 | 2.31 | 1.45 |
| 2004 | 1.99 | 2.72 | 1.39 |
| 2003 | 2.7 | 3.54 | 1.95 |
| 2002 | 3.46 | 3.96 | 2.81 |
| 2001 | 4.9 | 6.59 | 3.3 |
| 2000 | 7.45 | 9.66 | 5.21 |
| 1999 | 4.4 | 5.82 | 3.47 |
| 1998 | 4.96 | 6.08 | 3.78 |