| 时间 | 值 （%） | 世界排名 |
|---|---|---|
| 2016 | 3.028 | 59 |
| 2015 | 3.134 | 67 |
| 2014 | 3.048 | 72 |
| 2013 | 2.97 | 90 |
| 2012 | 2.981 | 101 |
| 2011 | 2.911 | 101 |
| 2010 | 2.503 | 114 |
| 2009 | 2.082 | 128 |
| 2008 | 3.126 | 130 |
| 2007 | 3.166 | 134 |
| 2006 | 3.149 | 118 |
| 2005 | 3.002 | 110 |
| 2004 | 3 | 105 |
| 2003 | 3.067 | 107 |
| 2002 | 3.205 | 110 |
| 2001 | 3.374 | 118 |
| 2000 | 3.363 | 126 |
| 1999 | 4.124 | 124 |
| 1998 | 8.513 | 69 |
| 1997 | 7.777 | 78 |
| 1996 | 7.085 | 85 |
| 1995 | 5.933 | 96 |
| 1994 | 4.893 | 97 |
| 1993 | 7.026 | 81 |
| 1992 | 7.935 | 63 |
| 1991 | 7.111 | 79 |
| 1990 | 5.721 | 97 |
| 1989 | 4.562 | 100 |
| 1988 | 3.292 | 105 |
| 1987 | 3 | 104 |
| 1986 | 7.083 | 68 |