| 时间 | 值 （%） | 世界排名 |
|---|---|---|
| 2016 | 76.18 | 83 |
| 2015 | 76.08 | 83 |
| 2014 | 75.91 | 84 |
| 2013 | 75.66 | 85 |
| 2012 | 75.71 | 85 |
| 2011 | 75.58 | 84 |
| 2010 | 75.56 | 82 |
| 2009 | 74.6 | 90 |
| 2008 | 73.97 | 100 |
| 2007 | 73.28 | 104 |
| 2006 | 73.03 | 105 |
| 2005 | 75.31 | 86 |
| 2004 | 74.08 | 96 |
| 2003 | 72.71 | 111 |
| 2002 | 71.27 | 125 |
| 2001 | 71.1 | 129 |
| 2000 | 72.51 | 118 |
| 1999 | 73.35 | 114 |
| 1998 | 71.13 | 130 |
| 1997 | 71.58 | 130 |
| 1996 | 72 | 124 |
| 1995 | 72.35 | 125 |
| 1994 | 73.46 | 118 |
| 1993 | 72.44 | 130 |
| 1992 | 70.79 | 145 |
| 1991 | 74.44 | 117 |
| 1990 | 74.68 | 117 |