| 时间 | 值 （%） | 世界排名 |
|---|---|---|
| 2016 | 51.47 | 76 |
| 2015 | 52.58 | 92 |
| 2014 | 53.76 | 103 |
| 2013 | 54.89 | 107 |
| 2012 | 55.97 | 111 |
| 2011 | 57.07 | 115 |
| 2010 | 58.24 | 116 |
| 2009 | 59.27 | 118 |
| 2008 | 60.29 | 118 |
| 2007 | 61.29 | 119 |
| 2006 | 62.24 | 119 |
| 2005 | 63.13 | 118 |
| 2004 | 64.37 | 118 |
| 2003 | 65.61 | 118 |
| 2002 | 66.84 | 115 |
| 2001 | 68.04 | 116 |
| 2000 | 69.18 | 115 |
| 1999 | 70.65 | 115 |
| 1998 | 72.12 | 112 |
| 1997 | 73.56 | 113 |
| 1996 | 74.98 | 114 |
| 1995 | 76.35 | 113 |
| 1994 | 77.94 | 113 |
| 1993 | 79.49 | 115 |
| 1992 | 80.97 | 117 |
| 1991 | 82.27 | 120 |
| 1990 | 83.34 | 121 |
| 1989 | 84.68 | 122 |
| 1988 | 85.75 | 124 |
| 1987 | 86.58 | 124 |
| 1986 | 87.32 | 127 |