| 时间 | 值 （%） | 世界排名 |
|---|---|---|
| 2016 | 70.98 | 115 |
| 2015 | 71.34 | 112 |
| 2014 | 71.79 | 108 |
| 2013 | 72.25 | 104 |
| 2012 | 72.74 | 99 |
| 2011 | 73.27 | 100 |
| 2010 | 73.86 | 98 |
| 2009 | 74.38 | 94 |
| 2008 | 74.88 | 91 |
| 2007 | 75.36 | 87 |
| 2006 | 75.79 | 82 |
| 2005 | 76.14 | 79 |
| 2004 | 76.38 | 77 |
| 2003 | 76.58 | 79 |
| 2002 | 76.75 | 76 |
| 2001 | 76.99 | 77 |
| 2000 | 77.3 | 78 |
| 1999 | 79.01 | 70 |
| 1998 | 79.42 | 69 |
| 1997 | 79.73 | 68 |
| 1996 | 79.93 | 71 |
| 1995 | 80 | 70 |
| 1994 | 79.98 | 72 |
| 1993 | 79.88 | 73 |
| 1992 | 79.73 | 74 |
| 1991 | 79.6 | 75 |
| 1990 | 79.52 | 73 |