时间(年) | 2000 | 2001 | 2002 | 2003 | 2004 | 2005 | 2006 | 2007 | 2008 |
| 0.1055 | 0.1326 | 0.1742 | 0.238 | 0.3827 | 0.5584 | 0.6401 | 0.7135 | 0.7918 |
2009 | 2010 | 2011 | 2012 | 2013 | 2014 | 2015 | 2016 | 2017 | 2018 |
0.8847 | 0.92 | 0.9 | 0.924 | 0.984 | 0.9629 | 1.0965 | 1.1 | 1.144 | 1.149 |