| 时间 | 平均 | 最高 | 最低 |
|---|---|---|---|
| 2025 | 1.02 | 1.15 | 0.88 |
| 2024 | 0.82 | 1.53 | 0.56 |
| 2023 | 0.84 | 1.21 | 0.71 |
| 2022 | 0.72 | 0.94 | 0.59 |
| 2021 | 0.73 | 1.01 | 0.53 |
| 2020 | 0.83 | 1.03 | 0.63 |
| 2019 | 1.01 | 1.54 | 0.78 |
| 2018 | 0.89 | 1.19 | 0.54 |
| 2017 | 1.51 | 1.95 | 1.14 |
| 2016 | 2.23 | 3.24 | 1.86 |
| 2015 | 4.7 | 6.11 | 2.36 |
| 2014 | 3.15 | 5.37 | 2 |
| 2013 | 3.31 | 5.39 | 2.58 |
| 2012 | 3.63 | 4.99 | 2.17 |
| 2011 | 4.22 | 4.94 | 3.39 |
| 2010 | 4.39 | 5.63 | 2.84 |
| 2009 | 4.07 | 5.36 | 3.26 |
| 2008 | 3.76 | 5.51 | 2.05 |
| 2007 | 3.31 | 5.86 | 1.46 |
| 2006 | 1.25 | 1.71 | 0.75 |
| 2005 | 1.02 | 1.51 | 0.69 |
| 2004 | 1.34 | 1.79 | 0.95 |
| 2003 | 1.5 | 1.75 | 1.21 |
| 2002 | 2.01 | 2.3 | 1.7 |
| 2001 | 3.01 | 3.78 | 2.15 |
| 2000 | 11.14 | 13.73 | 8.84 |