| 时间 | 值 （%） | 世界排名 |
|---|---|---|
| 2016 | 51.74 | 95 |
| 2015 | 53.42 | 101 |
| 2014 | 54.62 | 111 |
| 2013 | 53.27 | 119 |
| 2012 | 52.63 | 122 |
| 2011 | 55.72 | 117 |
| 2010 | 59.11 | 98 |
| 2009 | 49.29 | 119 |
| 2008 | 55.87 | 125 |
| 2007 | 65.9 | 87 |
| 2006 | 66.91 | 85 |
| 2005 | 70.42 | 75 |
| 2004 | 70.25 | 72 |
| 2003 | 70.12 | 60 |
| 2002 | 70.76 | 64 |
| 2001 | 72.75 | 59 |
| 2000 | 63.56 | 74 |
| 1999 | 52.16 | 97 |
| 1998 | 41.56 | 129 |
| 1997 | 39.23 | 135 |
| 1996 | 44.02 | 119 |
| 1995 | 46.25 | 112 |
| 1994 | 38.44 | 123 |
| 1993 | 83.38 | 25 |
| 1992 | 87.68 | 19 |
| 1991 | 79.62 | 28 |
| 1990 | 71.56 | 40 |
| 1989 | 71.61 | 37 |
| 1988 | 68.41 | 33 |
| 1987 | 66.24 | 35 |
| 1986 | 57.46 | 50 |