| 时间 | 平均 | 最高 | 最低 |
|---|---|---|---|
| 2025 | 0.97 | 1.04 | 0.88 |
| 2024 | 0.85 | 1.31 | 0.66 |
| 2023 | 0.94 | 1.2 | 0.8 |
| 2022 | 1.08 | 1.77 | 0.75 |
| 2021 | 1.22 | 1.52 | 1.09 |
| 2020 | 1.37 | 1.56 | 1.18 |
| 2019 | 1.63 | 2.06 | 1.37 |
| 2018 | 1.59 | 2.05 | 1.33 |
| 2017 | 1.94 | 3.29 | 1.54 |
| 2016 | 3.23 | 6.83 | 2.1 |
| 2015 | 3.9 | 8.11 | 2.19 |
| 2014 | 2.53 | 3.05 | 2.03 |
| 2013 | 3.49 | 4.93 | 2.6 |
| 2012 | 2.95 | 3.51 | 2.32 |
| 2011 | 3.17 | 4.08 | 2.53 |
| 2010 | 3.65 | 5.34 | 2.69 |
| 2009 | 5.26 | 7.67 | 2.7 |
| 2008 | 7.63 | 19.45 | 1.85 |
| 2007 | 11.88 | 22.38 | 2.29 |
| 2006 | 2.16 | 2.84 | 1.36 |
| 2005 | 1.59 | 4.44 | 0.95 |
| 2004 | 2.15 | 2.96 | 1.77 |
| 2003 | 2.21 | 2.55 | 1.7 |
| 2002 | 2.73 | 3.46 | 1.75 |
| 2001 | 3.61 | 4.63 | 2.4 |
| 2000 | 5.01 | 6.39 | 3.26 |
| 1999 | 3.57 | 4.82 | 2.84 |