| 时间 | 值 （%） | 世界排名 |
|---|---|---|
| 2016 | 50.91 | 72 |
| 2015 | 51.41 | 80 |
| 2014 | 52.09 | 89 |
| 2013 | 52.86 | 97 |
| 2012 | 53.69 | 103 |
| 2011 | 54.59 | 107 |
| 2010 | 55.52 | 109 |
| 2009 | 56.48 | 111 |
| 2008 | 57.45 | 110 |
| 2007 | 58.42 | 110 |
| 2006 | 59.41 | 111 |
| 2005 | 60.45 | 111 |
| 2004 | 61.24 | 110 |
| 2003 | 62.1 | 107 |
| 2002 | 63 | 107 |
| 2001 | 63.88 | 106 |
| 2000 | 64.74 | 105 |
| 1999 | 65.56 | 104 |
| 1998 | 66.34 | 102 |
| 1997 | 67.14 | 101 |
| 1996 | 68.02 | 100 |
| 1995 | 69.07 | 99 |
| 1994 | 70.28 | 99 |
| 1993 | 71.62 | 100 |
| 1992 | 73.09 | 102 |
| 1991 | 74.71 | 103 |
| 1990 | 76.43 | 105 |
| 1989 | 78.41 | 107 |
| 1988 | 80.67 | 111 |
| 1987 | 83.09 | 115 |
| 1986 | 85.48 | 122 |