| 时间 | 平均 | 最高 | 最低 |
|---|---|---|---|
| 2025 | 0.51 | 0.58 | 0.46 |
| 2024 | 0.43 | 0.73 | 0.32 |
| 2023 | 0.54 | 0.66 | 0.41 |
| 2022 | 0.64 | 1.01 | 0.46 |
| 2021 | 0.44 | 0.52 | 0.38 |
| 2020 | 0.55 | 0.73 | 0.46 |
| 2019 | 0.63 | 0.86 | 0.51 |
| 2018 | 0.85 | 1.26 | 0.55 |
| 2017 | 1.01 | 1.19 | 0.9 |
| 2016 | 1.05 | 1.52 | 0.88 |
| 2015 | 1.52 | 2.23 | 1.01 |
| 2014 | 0.83 | 1.71 | 0.66 |
| 2013 | 0.86 | 1.11 | 0.7 |
| 2012 | 1.01 | 1.26 | 0.79 |
| 2011 | 1.52 | 1.94 | 0.95 |
| 2010 | 2.32 | 3.69 | 1.68 |
| 2009 | 3.47 | 4.59 | 2.32 |
| 2008 | 53.15 | 124.81 | 22.86 |
| 2007 | 16.05 | 24.87 | 4.24 |
| 2006 | 3.99 | 7.42 | 1.4 |
| 2005 | 1.44 | 1.89 | 0.85 |
| 2004 | 2.15 | 3.45 | 1.22 |
| 2003 | 2.6 | 3.11 | 1.48 |
| 2002 | 16.57 | 19.02 | 14.44 |
| 2001 | 21 | 28.97 | 14.51 |
| 2000 | 15.18 | 23.49 | 9.89 |
| 1999 | 9.11 | 12.91 | 6.87 |
| 1998 | 7.21 | 10.66 | 2.41 |
| 1997 | 2.67 | 3.91 | 2.04 |