| 时间 | 平均 | 最高 | 最低 |
|---|---|---|---|
| 2025 | 0.94 | 1.12 | 0.81 |
| 2024 | 0.68 | 1.05 | 0.42 |
| 2023 | 1.01 | 1.24 | 0.83 |
| 2022 | 0.9 | 1.19 | 0.61 |
| 2021 | 0.62 | 1.02 | 0.45 |
| 2020 | 0.59 | 0.68 | 0.51 |
| 2019 | 0.68 | 0.85 | 0.57 |
| 2018 | 0.8 | 1.06 | 0.54 |
| 2017 | 1.18 | 1.59 | 0.98 |
| 2016 | 1.2 | 1.62 | 0.93 |
| 2015 | 1.6 | 2.59 | 0.95 |
| 2014 | 2.24 | 2.77 | 1.61 |
| 2013 | 2.07 | 3.22 | 1.56 |
| 2012 | 16.03 | 80.32 | 2.08 |
| 2011 | 23.47 | 67.72 | 12.74 |
| 2010 | 15.73 | 21.29 | 12.5 |
| 2009 | 13.7 | 23.77 | 6.52 |
| 2008 | 8.36 | 16.4 | 4.83 |
| 2007 | 11.93 | 17.25 | 3.54 |
| 2006 | 3.74 | 5.19 | 3.04 |
| 2005 | 3.85 | 4.66 | 2.93 |
| 2004 | 7.67 | 17.38 | 4.2 |
| 2003 | 9.94 | 18.38 | 6.95 |
| 2002 | 7.49 | 9.63 | 3.11 |
| 2001 | 6.83 | 8.26 | 4.81 |
| 2000 | 6.51 | 7.75 | 4.27 |
| 1999 | 4.54 | 5.63 | 3.53 |