| 时间 | 平均 | 最高 | 最低 |
|---|---|---|---|
| 2025 | 0.41 | 0.44 | 0.37 |
| 2024 | 0.37 | 0.46 | 0.34 |
| 2023 | 0.43 | 0.47 | 0.36 |
| 2022 | 0.39 | 0.46 | 0.31 |
| 2021 | 0.34 | 0.37 | 0.31 |
| 2020 | 0.4 | 0.52 | 0.33 |
| 2019 | 0.54 | 0.67 | 0.45 |
| 2018 | 0.64 | 0.85 | 0.47 |
| 2017 | 0.98 | 1.18 | 0.8 |
| 2016 | 1.07 | 1.3 | 0.94 |
| 2015 | 1.12 | 1.93 | 0.65 |
| 2014 | 1.04 | 1.24 | 0.9 |
| 2013 | 0.94 | 1.11 | 0.8 |
| 2012 | 0.72 | 0.85 | 0.6 |
| 2011 | 1.09 | 1.54 | 0.68 |
| 2010 | 1.13 | 1.45 | 0.88 |
| 2009 | 0.83 | 1.15 | 0.53 |
| 2008 | 0.9 | 1.72 | 0.44 |
| 2007 | 1.55 | 2.28 | 1.05 |
| 2006 | 0.85 | 1.05 | 0.75 |
| 2005 | 0.33 | 0.78 | 0.19 |
| 2004 | 0.33 | 0.46 | 0.24 |
| 2003 | 0.37 | 0.42 | 0.34 |
| 2002 | 0.44 | 0.54 | 0.35 |
| 2001 | 0.59 | 0.97 | 0.24 |
| 2000 | 0.22 | 0.28 | 0.18 |
| 1999 | 0.18 | 0.32 | 0.13 |