| 时间 | 值 （%） | 世界排名 |
|---|---|---|
| 2016 | 34.2 | 10 |
| 2015 | 34.37 | 9 |
| 2014 | 35.77 | 9 |
| 2013 | 37.23 | 10 |
| 2012 | 38.8 | 10 |
| 2011 | 44.3 | 6 |
| 2010 | 44.8 | 5 |
| 2009 | 58.04 | 1 |
| 2008 | 65.17 | 1 |
| 2007 | 65.6 | 1 |
| 2006 | 63.82 | 1 |
| 2005 | 66.03 | 1 |
| 2004 | 65.05 | 1 |
| 2003 | 72.24 | 1 |
| 2002 | 79.04 | 1 |
| 2001 | 76.53 | 1 |
| 2000 | 76.07 | 1 |
| 1999 | 76.19 | 1 |
| 1998 | 78.64 | 1 |
| 1997 | 76.95 | 1 |
| 1996 | 93.98 | 1 |
| 1995 | 81.82 | 1 |
| 1994 | 52.42 | 7 |
| 1993 | 50.62 | 10 |
| 1992 | 51.28 | 6 |
| 1991 | 55.6 | 3 |
| 1990 | 54.37 | 6 |
| 1989 | 38.73 | 16 |
| 1988 | 38.11 | 16 |
| 1987 | 38.13 | 14 |
| 1986 | 37.36 | 16 |