| 时间 | 值 （%） | 世界排名 |
|---|---|---|
| 2016 | 5.54 | 15 |
| 2015 | 5.73 | 54 |
| 2014 | 6.47 | 43 |
| 2013 | 6.44 | 38 |
| 2012 | 5.8 | 54 |
| 2011 | 6.47 | 50 |
| 2010 | 5.12 | 58 |
| 2009 | 5.28 | 58 |
| 2008 | 7.96 | 56 |
| 2007 | 8.38 | 60 |
| 2006 | 7.97 | 50 |
| 2005 | 7.66 | 34 |
| 2004 | 5.85 | 47 |
| 2003 | 4.5 | 51 |
| 2002 | 4.38 | 55 |
| 2001 | 3.91 | 59 |
| 2000 | 4.84 | 57 |
| 1999 | 4.36 | 61 |
| 1998 | 4.5 | 49 |
| 1997 | 3.25 | 61 |
| 1996 | 3.67 | 36 |
| 1995 | 2.93 | 48 |
| 1994 | 2.85 | 32 |
| 1993 | 2.59 | 30 |
| 1992 | 2.65 | 30 |
| 1991 | 2.49 | 36 |
| 1990 | 2.19 | 36 |
| 1989 | 1.48 | 41 |
| 1988 | 2.02 | 28 |
| 1987 | 1.37 | 38 |
| 1986 | 1.11 | 37 |