| 时间 | 值 （%） | 世界排名 |
|---|---|---|
| 2016 | 15.35 | 1 |
| 2015 | 15.19 | 1 |
| 2014 | 14.9 | 1 |
| 2013 | 14.9 | 1 |
| 2012 | 15.15 | 1 |
| 2011 | 15.52 | 2 |
| 2010 | 15.89 | 4 |
| 2009 | 16.42 | 3 |
| 2008 | 17.06 | 1 |
| 2007 | 17.79 | 1 |
| 2006 | 18.61 | 1 |
| 2005 | 19.55 | 1 |
| 2004 | 20.28 | 3 |
| 2003 | 21 | 4 |
| 2002 | 21.73 | 6 |
| 2001 | 22.51 | 7 |
| 2000 | 23.39 | 8 |
| 1999 | 23.89 | 8 |
| 1998 | 24.45 | 7 |
| 1997 | 25.1 | 8 |
| 1996 | 25.72 | 8 |
| 1995 | 26.14 | 9 |
| 1994 | 26.83 | 12 |
| 1993 | 27.47 | 13 |
| 1992 | 28.06 | 13 |
| 1991 | 28.71 | 15 |
| 1990 | 29.48 | 17 |
| 1989 | 30.26 | 17 |
| 1988 | 31.1 | 19 |
| 1987 | 32.02 | 20 |
| 1986 | 32.97 | 24 |