| 时间 | 值 （%） | 世界排名 |
|---|---|---|
| 2016 | 28.02 | 64 |
| 2015 | 27.87 | 76 |
| 2014 | 27.14 | 83 |
| 2013 | 27.58 | 80 |
| 2012 | 28.89 | 70 |
| 2011 | 29.29 | 71 |
| 2010 | 27.38 | 88 |
| 2009 | 30.46 | 56 |
| 2008 | 29.47 | 71 |
| 2007 | 30.53 | 70 |
| 2006 | 29.76 | 74 |
| 2005 | 28.24 | 84 |
| 2004 | 26.66 | 93 |
| 2003 | 27.52 | 85 |
| 2002 | 26.69 | 90 |
| 2001 | 26.9 | 89 |
| 2000 | 25.85 | 96 |
| 1999 | 25.15 | 99 |
| 1998 | 24.61 | 102 |
| 1997 | 23.67 | 109 |
| 1996 | 21.35 | 119 |
| 1995 | 28.37 | 89 |
| 1994 | 34.77 | 37 |
| 1993 | 37.18 | 30 |
| 1992 | 43.49 | 17 |
| 1991 | 43.76 | 16 |
| 1990 | 49.2 | 9 |
| 1989 | 57.62 | 4 |
| 1988 | 58.12 | 3 |
| 1987 | 59.49 | 4 |
| 1986 | 65.12 | 2 |