| 时间 | 平均 | 最高 | 最低 |
|---|---|---|---|
| 2025 | 1.01 | 1.08 | 0.92 |
| 2024 | 0.94 | 1.38 | 0.78 |
| 2023 | 1.07 | 1.41 | 0.89 |
| 2022 | 1 | 1.23 | 0.89 |
| 2021 | 1.1 | 1.3 | 1.01 |
| 2020 | 1.38 | 1.66 | 1.22 |
| 2019 | 1.61 | 2.4 | 1.03 |
| 2018 | 1.41 | 1.83 | 1.03 |
| 2017 | 2.23 | 3.06 | 1.61 |
| 2016 | 2.88 | 5.7 | 2.04 |
| 2015 | 3.85 | 6.13 | 2.17 |
| 2014 | 2.62 | 4.39 | 2.12 |
| 2013 | 3.01 | 3.93 | 2.29 |
| 2012 | 5.75 | 12.14 | 1.85 |
| 2011 | 5.44 | 6.71 | 4.39 |
| 2010 | 6.9 | 9.47 | 4.81 |
| 2009 | 7.8 | 10.06 | 6.15 |
| 2008 | 9.7 | 19.21 | 5.41 |
| 2007 | 14.56 | 23.3 | 7.28 |
| 2006 | 5.76 | 8 | 4.04 |
| 2005 | 4.02 | 5.18 | 3.34 |
| 2004 | 4.37 | 6.47 | 2.96 |
| 2003 | 5.52 | 7.32 | 3.93 |
| 2002 | 5.22 | 6.51 | 3.32 |
| 2001 | 6.93 | 8.26 | 5.64 |
| 2000 | 7.15 | 7.69 | 6.7 |