| 时间 | 值 （%） | 世界排名 |
|---|---|---|
| 2016 | 81.24 | 6 |
| 2015 | 81.21 | 6 |
| 2014 | 81.2 | 6 |
| 2013 | 81.14 | 6 |
| 2012 | 82.12 | 5 |
| 2011 | 82.91 | 5 |
| 2010 | 83.6 | 5 |
| 2009 | 84.27 | 5 |
| 2008 | 84.91 | 5 |
| 2007 | 82.63 | 6 |
| 2006 | 81.26 | 7 |
| 2005 | 78.65 | 10 |
| 2004 | 78.27 | 11 |
| 2003 | 77.88 | 12 |
| 2002 | 77.47 | 11 |
| 2001 | 77.05 | 10 |
| 2000 | 76.6 | 11 |
| 1999 | 76.13 | 11 |
| 1998 | 75.63 | 11 |
| 1997 | 75.61 | 12 |
| 1996 | 75.58 | 12 |
| 1995 | 75.56 | 12 |
| 1994 | 75.61 | 12 |
| 1993 | 75.66 | 13 |
| 1992 | 75.71 | 14 |
| 1991 | 75.75 | 14 |
| 1990 | 75.76 | 15 |