| 时间 | 值 （%） | 世界排名 |
|---|---|---|
| 2016 | 55.15 | 81 |
| 2015 | 54.89 | 82 |
| 2014 | 54.59 | 84 |
| 2013 | 54.42 | 84 |
| 2012 | 53.8 | 87 |
| 2011 | 53.79 | 85 |
| 2010 | 50.93 | 102 |
| 2009 | 49.97 | 106 |
| 2008 | 48.24 | 114 |
| 2007 | 48.18 | 113 |
| 2006 | 48.36 | 111 |
| 2005 | 48.54 | 109 |
| 2004 | 48.72 | 109 |
| 2003 | 48.81 | 109 |
| 2002 | 48.89 | 109 |
| 2001 | 48.86 | 110 |
| 2000 | 49.1 | 101 |
| 1999 | 49.31 | 97 |
| 1998 | 49.49 | 94 |
| 1997 | 49.79 | 93 |
| 1996 | 50.06 | 91 |
| 1995 | 50.4 | 88 |
| 1994 | 50.8 | 86 |
| 1993 | 51.15 | 84 |
| 1992 | 51.24 | 85 |
| 1991 | 50.38 | 86 |
| 1990 | 50.26 | 85 |