| 时间 | 平均 | 最高 | 最低 |
|---|---|---|---|
| 2025 | 0.59 | 0.74 | 0.52 |
| 2024 | 0.56 | 0.65 | 0.47 |
| 2023 | 0.61 | 0.88 | 0.56 |
| 2022 | 0.69 | 0.82 | 0.57 |
| 2021 | 0.79 | 1.18 | 0.68 |
| 2020 | 0.69 | 0.83 | 0.59 |
| 2019 | 0.69 | 0.96 | 0.6 |
| 2018 | 0.86 | 1.23 | 0.65 |
| 2017 | 1.09 | 1.31 | 0.86 |
| 2016 | 0.89 | 1.04 | 0.74 |
| 2015 | 1.05 | 1.97 | 0.76 |
| 2014 | 0.59 | 0.89 | 0.48 |
| 2013 | 0.58 | 0.68 | 0.48 |
| 2012 | 0.68 | 0.88 | 0.58 |
| 2011 | 0.99 | 1.2 | 0.65 |
| 2010 | 1.36 | 2.2 | 0.98 |
| 2009 | 1.6 | 2.23 | 0.93 |
| 2008 | 2.45 | 5.12 | 0.82 |
| 2007 | 4.02 | 6.41 | 2.27 |
| 2006 | 1.48 | 2.57 | 1.15 |
| 2005 | 1.4 | 1.79 | 0.99 |
| 2004 | 1.83 | 2.7 | 1.53 |
| 2003 | 2.05 | 2.51 | 1.69 |
| 2002 | 2.1 | 2.28 | 1.78 |
| 2001 | 2.41 | 2.77 | 1.92 |