| 时间 | 平均 | 最高 | 最低 |
|---|---|---|---|
| 2025 | 0.42 | 0.49 | 0.33 |
| 2024 | 0.33 | 0.42 | 0.27 |
| 2023 | 0.35 | 0.42 | 0.28 |
| 2022 | 0.33 | 0.43 | 0.27 |
| 2021 | 0.32 | 0.52 | 0.2 |
| 2020 | 0.29 | 0.36 | 0.23 |
| 2019 | 0.38 | 0.43 | 0.33 |
| 2018 | 0.52 | 0.76 | 0.37 |
| 2017 | 0.63 | 0.78 | 0.56 |
| 2016 | 0.54 | 0.65 | 0.41 |
| 2015 | 0.54 | 0.77 | 0.43 |
| 2014 | 0.42 | 0.5 | 0.37 |
| 2013 | 0.43 | 0.53 | 0.36 |
| 2012 | 0.41 | 0.49 | 0.34 |
| 2011 | 0.59 | 0.81 | 0.39 |
| 2010 | 0.71 | 0.84 | 0.58 |
| 2009 | 0.7 | 0.96 | 0.43 |
| 2008 | 0.86 | 1.65 | 0.31 |
| 2007 | 1.5 | 2.02 | 1.03 |
| 2006 | 0.85 | 2.2 | 0.53 |
| 2005 | 0.29 | 0.54 | 0.18 |
| 2004 | 0.3 | 0.41 | 0.22 |
| 2003 | 0.33 | 0.37 | 0.3 |
| 2002 | 0.37 | 0.42 | 0.31 |
| 2001 | 0.42 | 0.66 | 0.21 |
| 2000 | 0.2 | 0.27 | 0.14 |
| 1999 | 0.17 | 0.3 | 0.1 |
| 1998 | 0.17 | 0.24 | 0.1 |