| 时间 | 值 （%） | 世界排名 |
|---|---|---|
| 2016 | 24.33 | 82 |
| 2015 | 25.4 | 94 |
| 2014 | 27.28 | 81 |
| 2013 | 26.91 | 88 |
| 2012 | 28.22 | 77 |
| 2011 | 28.5 | 78 |
| 2010 | 27.07 | 91 |
| 2009 | 28.91 | 66 |
| 2008 | 27.73 | 88 |
| 2007 | 27.89 | 86 |
| 2006 | 27.88 | 88 |
| 2005 | 26.76 | 95 |
| 2004 | 26.19 | 97 |
| 2003 | 26.36 | 93 |
| 2002 | 25.76 | 97 |
| 2001 | 25.94 | 97 |
| 2000 | 26.75 | 90 |
| 1999 | 26.83 | 88 |
| 1998 | 27.7 | 83 |
| 1997 | 27.62 | 88 |
| 1996 | 28.45 | 87 |
| 1995 | 28.96 | 85 |
| 1994 | 29.1 | 68 |
| 1993 | 29.14 | 72 |
| 1992 | 29.45 | 66 |
| 1991 | 30.21 | 65 |
| 1990 | 31.31 | 60 |