| 时间 | 值 （%） | 世界排名 |
|---|---|---|
| 2016 | 1.1 | 141 |
| 2015 | 1.15 | 135 |
| 2014 | 1.19 | 130 |
| 2013 | 1.23 | 125 |
| 2012 | 1.27 | 123 |
| 2011 | 1.3 | 122 |
| 2010 | 1.32 | 126 |
| 2009 | 1.34 | 125 |
| 2008 | 1.38 | 125 |
| 2007 | 1.43 | 124 |
| 2006 | 1.49 | 125 |
| 2005 | 1.55 | 124 |
| 2004 | 1.61 | 120 |
| 2003 | 1.68 | 120 |
| 2002 | 1.74 | 116 |
| 2001 | 1.84 | 115 |
| 2000 | 2.31 | 93 |
| 1999 | 2.4 | 87 |
| 1998 | 2.48 | 86 |
| 1997 | 2.53 | 91 |
| 1996 | 2.49 | 89 |
| 1995 | 2.52 | 90 |
| 1994 | 2.57 | 91 |
| 1993 | 2.62 | 93 |
| 1992 | 2.69 | 90 |
| 1991 | 2.78 | 95 |
| 1990 | 2.86 | 94 |
| 1989 | 2.95 | 96 |
| 1988 | 3.04 | 95 |
| 1987 | 3.14 | 96 |
| 1986 | 3.26 | 93 |