| 时间 | 平均 | 最高 | 最低 |
|---|---|---|---|
| 2025 | 0.95 | 1.01 | 0.87 |
| 2024 | 0.96 | 1.24 | 0.8 |
| 2023 | 1.1 | 1.27 | 0.99 |
| 2022 | 1.2 | 1.48 | 0.93 |
| 2021 | 1.67 | 2.4 | 1.33 |
| 2020 | 1.82 | 2.63 | 1.16 |
| 2019 | 1.41 | 1.93 | 1.12 |
| 2018 | 1.25 | 1.7 | 0.93 |
| 2017 | 2.04 | 2.48 | 1.55 |
| 2016 | 2.4 | 2.87 | 2.01 |
| 2015 | 5.49 | 9.72 | 2.19 |
| 2014 | 4.31 | 7.96 | 3.3 |
| 2013 | 3.78 | 7.33 | 2.22 |
| 2012 | 3.98 | 6.84 | 2.88 |
| 2011 | 4.41 | 5.75 | 2.9 |
| 2010 | 6.6 | 10.16 | 4.86 |
| 2009 | 8.78 | 12.19 | 4.98 |
| 2008 | 9.27 | 23.66 | 4.39 |
| 2007 | 13.81 | 22.68 | 2.87 |
| 2006 | 3.14 | 8.39 | 1.53 |
| 2005 | 1.82 | 2.31 | 1.28 |
| 2004 | 3.27 | 4.87 | 2.24 |
| 2003 | 295.36 | 1131.22 | 3.35 |
| 2002 | 400.08 | 1045.53 | 77.85 |
| 2001 | 27.51 | 31.57 | 20.98 |
| 2000 | 17.19 | 22.55 | 9.21 |
| 1999 | 7.05 | 9.87 | 5.27 |
| 1998 | 7.93 | 10.46 | 4.21 |