| 时间 | 值 （%） | 世界排名 |
|---|---|---|
| 2016 | 1.85 | 101 |
| 2015 | 2.04 | 97 |
| 2014 | 2.22 | 88 |
| 2013 | 2.34 | 84 |
| 2012 | 2.35 | 84 |
| 2011 | 2.3 | 86 |
| 2010 | 2.19 | 90 |
| 2009 | 2.11 | 96 |
| 2008 | 2.07 | 98 |
| 2007 | 2.11 | 93 |
| 2006 | 2.21 | 92 |
| 2005 | 2.33 | 87 |
| 2004 | 2.43 | 82 |
| 2003 | 2.48 | 81 |
| 2002 | 2.44 | 86 |
| 2001 | 2.33 | 96 |
| 2000 | 2.21 | 96 |
| 1999 | 2.12 | 95 |
| 1998 | 2.04 | 101 |
| 1997 | 2.03 | 103 |
| 1996 | 2.09 | 105 |
| 1995 | 2.04 | 107 |
| 1994 | 2.06 | 108 |
| 1993 | 2.18 | 109 |
| 1992 | 2.46 | 101 |
| 1991 | 2.86 | 90 |
| 1990 | 3.31 | 82 |
| 1989 | 3.74 | 73 |
| 1988 | 4.08 | 70 |
| 1987 | 4.26 | 66 |
| 1986 | 4.29 | 66 |