| 时间 | 平均 | 最高 | 最低 |
|---|---|---|---|
| 2025 | 0.85 | 0.88 | 0.83 |
| 2024 | 0.75 | 1.07 | 0.61 |
| 2023 | 0.75 | 0.84 | 0.68 |
| 2022 | 0.78 | 1 | 0.67 |
| 2021 | 1.02 | 1.33 | 0.91 |
| 2020 | 1.33 | 1.61 | 1.05 |
| 2019 | 1.26 | 1.56 | 0.86 |
| 2018 | 1.02 | 1.44 | 0.75 |
| 2017 | 1.53 | 1.77 | 1.27 |
| 2016 | 1.63 | 1.82 | 1.27 |
| 2015 | 2.79 | 4.48 | 1.36 |
| 2014 | 1.66 | 3.55 | 1.37 |
| 2013 | 1.8 | 2.21 | 1.44 |
| 2012 | 1.72 | 2.2 | 1.29 |
| 2011 | 1.65 | 2.02 | 1.32 |
| 2010 | 2.39 | 3.78 | 1.65 |
| 2009 | 3.03 | 4 | 1.92 |
| 2008 | 8.24 | 26.93 | 1.57 |
| 2007 | 31.63 | 224.32 | 3.87 |
| 2006 | 3.65 | 85.56 | 2.51 |
| 2005 | 4.05 | 5.76 | 2.82 |
| 2004 | 5.55 | 7.49 | 3.15 |
| 2003 | 5.7 | 7.14 | 2.99 |
| 2002 | 5.42 | 6.3 | 4.47 |
| 2001 | 3.98 | 4.89 | 3.04 |
| 2000 | 0 | -0.46 | |
| 1999 | 0 | -1.88 | |
| 1998 | 78.17 | 107.21 | 58.17 |
| 1997 | 4.36 | 7.44 | 3.21 |