| 时间 | 值 （%） | 世界排名 |
|---|---|---|
| 2016 | 79.78 | 25 |
| 2015 | 79.74 | 25 |
| 2014 | 79.7 | 25 |
| 2013 | 79.85 | 27 |
| 2012 | 76.22 | 40 |
| 2011 | 76.21 | 39 |
| 2010 | 75.74 | 40 |
| 2009 | 75.75 | 39 |
| 2008 | 75.69 | 42 |
| 2007 | 75.73 | 45 |
| 2006 | 75.73 | 44 |
| 2005 | 75.74 | 44 |
| 2004 | 75.76 | 43 |
| 2003 | 75.79 | 44 |
| 2002 | 75.78 | 45 |
| 2001 | 75.81 | 52 |
| 2000 | 75.86 | 47 |
| 1999 | 75.87 | 47 |
| 1998 | 75.91 | 51 |
| 1997 | 75.94 | 52 |
| 1996 | 75.99 | 53 |
| 1995 | 76.04 | 55 |
| 1994 | 76.09 | 54 |
| 1993 | 76.12 | 57 |
| 1992 | 76.18 | 58 |
| 1991 | 76.22 | 57 |