| 时间 | 值 （%） | 世界排名 |
|---|---|---|
| 2016 | 76.72 | 37 |
| 2015 | 76.55 | 40 |
| 2014 | 76.39 | 41 |
| 2013 | 76.16 | 43 |
| 2012 | 75.86 | 42 |
| 2011 | 75.5 | 45 |
| 2010 | 75.24 | 46 |
| 2009 | 75.08 | 44 |
| 2008 | 74.74 | 52 |
| 2007 | 74.53 | 53 |
| 2006 | 74.41 | 54 |
| 2005 | 74.44 | 54 |
| 2004 | 74.57 | 51 |
| 2003 | 74.77 | 51 |
| 2002 | 75.08 | 51 |
| 2001 | 75.36 | 54 |
| 2000 | 75.64 | 48 |
| 1999 | 75.89 | 46 |
| 1998 | 76.27 | 47 |
| 1997 | 76.56 | 49 |
| 1996 | 76.8 | 49 |
| 1995 | 76.94 | 49 |
| 1994 | 77.04 | 48 |
| 1993 | 77.07 | 51 |
| 1992 | 77.14 | 52 |
| 1991 | 77.15 | 54 |