| 时间 | 值 （%） | 世界排名 |
|---|---|---|
| 2016 | 74.43 | 92 |
| 2015 | 74.33 | 92 |
| 2014 | 74.24 | 93 |
| 2013 | 74.34 | 93 |
| 2012 | 74.83 | 90 |
| 2011 | 75.43 | 88 |
| 2010 | 75.24 | 87 |
| 2009 | 75.81 | 78 |
| 2008 | 76.22 | 76 |
| 2007 | 76.3 | 78 |
| 2006 | 76.5 | 76 |
| 2005 | 77.17 | 69 |
| 2004 | 77.93 | 67 |
| 2003 | 77.74 | 70 |
| 2002 | 77.78 | 70 |
| 2001 | 78.33 | 70 |
| 2000 | 78.88 | 70 |
| 1999 | 79.59 | 65 |
| 1998 | 79.5 | 68 |
| 1997 | 80.03 | 66 |
| 1996 | 79.69 | 73 |
| 1995 | 80.62 | 65 |
| 1994 | 79.9 | 73 |
| 1993 | 80.67 | 62 |
| 1992 | 80.39 | 67 |
| 1991 | 79.89 | 72 |
| 1990 | 80.27 | 71 |