| 时间 | 值 （%） | 世界排名 |
|---|---|---|
| 2016 | 0.312 | 130 |
| 2015 | 0.366 | 145 |
| 2014 | 0.581 | 144 |
| 2013 | 0.724 | 144 |
| 2012 | 1.159 | 138 |
| 2011 | 1.403 | 138 |
| 2010 | 1.097 | 145 |
| 2009 | 1.383 | 146 |
| 2008 | 4.133 | 100 |
| 2007 | 3.754 | 115 |
| 2006 | 2.608 | 136 |
| 2005 | 1.913 | 142 |
| 2004 | 1.93 | 127 |
| 2003 | 2.147 | 124 |
| 2002 | 2.653 | 124 |
| 2001 | 3.557 | 116 |
| 2000 | 3.398 | 125 |
| 1999 | 2.427 | 136 |
| 1998 | 2.878 | 143 |
| 1997 | 2.693 | 136 |
| 1996 | 2.832 | 133 |
| 1995 | 3.852 | 127 |
| 1994 | 4.471 | 105 |
| 1993 | 6.272 | 85 |
| 1992 | 8.006 | 60 |
| 1991 | 7.623 | 67 |
| 1990 | 7.068 | 78 |
| 1989 | 5.501 | 92 |
| 1988 | 3.288 | 106 |
| 1987 | 3.204 | 101 |
| 1986 | 3.706 | 102 |