| 时间 | 值 （%） | 世界排名 |
|---|---|---|
| 2016 | 52.4 | 67 |
| 2015 | 51.98 | 69 |
| 2014 | 51.46 | 72 |
| 2013 | 51.2 | 72 |
| 2012 | 50.89 | 72 |
| 2011 | 50.71 | 74 |
| 2010 | 50.14 | 71 |
| 2009 | 49.48 | 77 |
| 2008 | 48.57 | 84 |
| 2007 | 47.65 | 88 |
| 2006 | 48.13 | 87 |
| 2005 | 48.81 | 79 |
| 2004 | 49.43 | 67 |
| 2003 | 50.02 | 67 |
| 2002 | 50.56 | 67 |
| 2001 | 51.07 | 65 |
| 2000 | 51.55 | 61 |
| 1999 | 52.14 | 59 |
| 1998 | 48.75 | 69 |
| 1997 | 48.79 | 72 |
| 1996 | 48.83 | 71 |
| 1995 | 48.95 | 68 |
| 1994 | 48.29 | 69 |
| 1993 | 48.36 | 70 |
| 1992 | 48.28 | 71 |
| 1991 | 48.18 | 74 |