| 时间 | 值 （%） | 世界排名 |
|---|---|---|
| 2016 | 18.59 | 16 |
| 2015 | -7.83 | 147 |
| 2014 | 3.61 | 135 |
| 2013 | 5.67 | 121 |
| 2012 | 12.89 | 60 |
| 2011 | 13.32 | 63 |
| 2010 | 15.81 | 59 |
| 2009 | 10.46 | 81 |
| 2008 | 12.24 | 99 |
| 2007 | 13.04 | 113 |
| 2006 | 16.99 | 87 |
| 2005 | 6.01 | 143 |
| 2004 | 9.67 | 109 |
| 2003 | 9.48 | 102 |
| 2002 | 8.12 | 103 |
| 2001 | 16.85 | 71 |
| 2000 | 9.95 | 101 |
| 1999 | 10.22 | 104 |
| 1998 | 7.79 | 100 |
| 1997 | 10.85 | 98 |
| 1996 | 21.09 | 52 |
| 1995 | 24.07 | 51 |
| 1994 | 15.24 | 85 |
| 1993 | 21.17 | 60 |
| 1992 | 61.56 | 15 |
| 1991 | 71.56 | 11 |
| 1990 | 51.95 | 17 |
| 1989 | 49.72 | 17 |
| 1988 | 34.76 | 21 |
| 1987 | 43.8 | 19 |
| 1986 | 21.87 | 37 |