| 时间 | 值 （%） | 世界排名 |
|---|---|---|
| 2016 | 0.98 | 105 |
| 2015 | 1.07 | 108 |
| 2014 | 1.03 | 108 |
| 2013 | 1.39 | 82 |
| 2012 | 1.49 | 71 |
| 2011 | 1.61 | 60 |
| 2010 | 1.61 | 66 |
| 2009 | 1.79 | 64 |
| 2008 | 1.52 | 79 |
| 2007 | 2.22 | 48 |
| 2006 | 1.74 | 68 |
| 2005 | 1.43 | 92 |
| 2004 | 1.72 | 75 |
| 2003 | 1.61 | 81 |
| 2002 | 1.68 | 76 |
| 2001 | 1.98 | 60 |
| 2000 | 1.9 | 60 |
| 1999 | 1.23 | 102 |
| 1998 | 1.36 | 97 |
| 1997 | 1.48 | 95 |
| 1996 | 1.54 | 87 |
| 1995 | 1.76 | 76 |
| 1994 | 1.84 | 79 |
| 1993 | 1.96 | 76 |
| 1992 | 1.99 | 77 |
| 1991 | 2.35 | 63 |
| 1990 | 2.28 | 68 |
| 1989 | 2.46 | 59 |
| 1988 | 2.22 | 69 |
| 1987 | 2.13 | 71 |
| 1986 | 1.13 | 96 |