| 时间 | 值 （%） | 世界排名 |
|---|---|---|
| 2016 | 1.25 | 83 |
| 2015 | 1.42 | 78 |
| 2014 | 1.29 | 89 |
| 2013 | 1.28 | 90 |
| 2012 | 1.3 | 88 |
| 2011 | 1.14 | 98 |
| 2010 | 1.02 | 110 |
| 2009 | 1.06 | 114 |
| 2008 | 0.91 | 124 |
| 2007 | 0.96 | 116 |
| 2006 | 1 | 117 |
| 2005 | 0.89 | 127 |
| 2004 | 1.05 | 121 |
| 2003 | 0.96 | 123 |
| 2002 | 1.1 | 115 |
| 2001 | 1.19 | 109 |
| 2000 | 1.35 | 96 |
| 1999 | 1.39 | 91 |
| 1998 | 1.54 | 84 |
| 1997 | 1.69 | 76 |
| 1996 | 2.06 | 62 |
| 1995 | 2.28 | 57 |
| 1994 | 2.05 | 67 |
| 1993 | 2.18 | 67 |
| 1992 | 2.37 | 61 |
| 1991 | 2.83 | 50 |
| 1990 | 1.97 | 81 |
| 1989 | 2.13 | 73 |
| 1988 | 2.86 | 47 |
| 1987 | 2.55 | 58 |
| 1986 | 3.65 | 38 |