| 时间 | 平均 | 最高 | 最低 |
|---|---|---|---|
| 2025 | 0.25 | 0.61 | 0.08 |
| 2024 | 0.23 | 0.27 | 0.17 |
| 2023 | 0.3 | 0.39 | 0.23 |
| 2022 | 0.36 | 0.43 | 0.32 |
| 2021 | 0.49 | 0.71 | 0.31 |
| 2020 | 0.31 | 0.38 | 0.28 |
| 2019 | 0.39 | 0.52 | 0.29 |
| 2018 | 0.6 | 0.84 | 0.41 |
| 2017 | 0.77 | 1.21 | 0.61 |
| 2016 | 0.54 | 0.63 | 0.46 |
| 2015 | 0.55 | 0.77 | 0.42 |
| 2014 | 0.43 | 0.52 | 0.38 |
| 2013 | 0.44 | 0.48 | 0.4 |
| 2012 | 0.42 | 0.53 | 0.33 |
| 2011 | 0.66 | 0.88 | 0.43 |
| 2010 | 0.82 | 0.94 | 0.71 |
| 2009 | 0.72 | 0.96 | 0.47 |
| 2008 | 1.1 | 1.86 | 0.37 |
| 2007 | 1.64 | 2.18 | 1.06 |
| 2006 | 0.99 | 1.2 | 0.8 |
| 2005 | 0.5 | 0.87 | 0.28 |
| 2004 | 0.53 | 0.96 | 0.32 |
| 2003 | 0.67 | 0.87 | 0.32 |
| 2002 | 0.52 | 0.64 | 0.44 |
| 2001 | 0.61 | 0.98 | 0.29 |
| 2000 | 0.53 | 0.67 | 0.39 |
| 1999 | 0.48 | 0.82 | 0.28 |
| 1998 | 0.59 | 0.82 | 0.36 |