| 时间 | 平均 | 最高 | 最低 |
|---|---|---|---|
| 2025 | 1.1 | 1.54 | 0.99 |
| 2024 | 1.21 | 1.63 | 0.95 |
| 2023 | 1.18 | 1.81 | 0.92 |
| 2022 | 1.18 | 1.62 | 0.98 |
| 2021 | 1.2 | 1.61 | 0.94 |
| 2020 | 0.93 | 1.22 | 0.8 |
| 2019 | 1.12 | 1.6 | 0.89 |
| 2018 | 1.2 | 1.53 | 0.88 |
| 2017 | 1.76 | 2.3 | 1.38 |
| 2016 | 1.92 | 2.35 | 1.54 |
| 2015 | 2.12 | 3.22 | 1.35 |
| 2014 | 1.71 | 2.67 | 1.26 |
| 2013 | 1.67 | 2.3 | 1.22 |
| 2012 | 2.28 | 3.18 | 1.49 |
| 2011 | 2.74 | 3.39 | 2.12 |
| 2010 | 0 | -3.38 | |
| 2009 | 25.52 | 42.74 | 5.33 |
| 2008 | 485.27 | 1391.62 | 5.18 |
| 2007 | 11.05 | 21.18 | 3.33 |
| 2006 | 3.35 | 4.01 | 2.59 |
| 2005 | 3.77 | 5.57 | 2.72 |
| 2004 | 8.47 | 16.55 | 5.03 |
| 2003 | 13.49 | 14.87 | 9.63 |
| 2002 | 14.04 | 18.39 | 9.2 |
| 2001 | 12.27 | 15.03 | 10.22 |
| 2000 | 8.85 | 13.13 | 5.19 |
| 1999 | 5.46 | 6.91 | 4.07 |
| 1998 | 4.42 | 5.23 | 3.4 |