| 时间 | 值 （%） | 世界排名 |
|---|---|---|
| 2016 | 0.83 | 82 |
| 2015 | 0.88 | 82 |
| 2014 | 0.93 | 79 |
| 2013 | 0.99 | 77 |
| 2012 | 1.04 | 75 |
| 2011 | 1.09 | 71 |
| 2010 | 1.12 | 73 |
| 2009 | 1.15 | 74 |
| 2008 | 1.17 | 76 |
| 2007 | 1.17 | 73 |
| 2006 | 1.16 | 78 |
| 2005 | 1.14 | 74 |
| 2004 | 1.13 | 79 |
| 2003 | 1.14 | 75 |
| 2002 | 0.87 | 88 |
| 2001 | 0.49 | 106 |
| 2000 | 0.58 | 100 |
| 1999 | 0.66 | 100 |
| 1998 | 0.75 | 92 |
| 1997 | 0.82 | 95 |
| 1996 | 0.88 | 94 |
| 1995 | 0.95 | 90 |
| 1994 | 1.02 | 89 |
| 1993 | 1.09 | 91 |
| 1992 | 1.14 | 89 |
| 1991 | 0.96 | 96 |
| 1990 | 0.68 | 112 |
| 1989 | 0.74 | 108 |
| 1988 | 0.78 | 106 |
| 1987 | 0.83 | 108 |
| 1986 | 0.87 | 108 |