| 时间 | 值 （%） | 世界排名 |
|---|---|---|
| 2016 | 74.21 | 93 |
| 2015 | 73.89 | 94 |
| 2014 | 73.59 | 95 |
| 2013 | 73.65 | 96 |
| 2012 | 73.48 | 98 |
| 2011 | 73.32 | 99 |
| 2010 | 73.16 | 100 |
| 2009 | 73.04 | 104 |
| 2008 | 72.94 | 106 |
| 2007 | 73.74 | 100 |
| 2006 | 74.61 | 95 |
| 2005 | 75.55 | 83 |
| 2004 | 76.54 | 76 |
| 2003 | 77.53 | 71 |
| 2002 | 78.51 | 69 |
| 2001 | 79.48 | 63 |
| 2000 | 80.43 | 58 |
| 1999 | 81.35 | 50 |
| 1998 | 81.54 | 49 |
| 1997 | 81.69 | 50 |
| 1996 | 81.86 | 49 |
| 1995 | 82.08 | 48 |
| 1994 | 82.39 | 45 |
| 1993 | 82.78 | 44 |
| 1992 | 83.21 | 43 |
| 1991 | 83.62 | 41 |
| 1990 | 83.98 | 39 |