| 时间 | 值 （%） | 世界排名 |
|---|---|---|
| 2016 | 2.142 | 77 |
| 2015 | 2.304 | 87 |
| 2014 | 2.904 | 76 |
| 2013 | 3.25 | 77 |
| 2012 | 3.917 | 72 |
| 2011 | 4.338 | 65 |
| 2010 | 4.213 | 70 |
| 2009 | 3.079 | 112 |
| 2008 | 4.725 | 85 |
| 2007 | 4.529 | 92 |
| 2006 | 4.063 | 100 |
| 2005 | 3.892 | 86 |
| 2004 | 3.85 | 82 |
| 2003 | 3.508 | 98 |
| 2002 | 3.704 | 104 |
| 2001 | 3.86 | 115 |
| 2000 | 5.068 | 95 |
| 1999 | 4.192 | 122 |
| 1998 | 4.479 | 120 |
| 1997 | 5.214 | 102 |
| 1996 | 6.9 | 88 |
| 1995 | 7.383 | 81 |
| 1994 | 5.939 | 89 |
| 1993 | 5.954 | 87 |
| 1992 | 7.358 | 78 |
| 1991 | 11.414 | 49 |
| 1990 | 16.347 | 31 |
| 1989 | 18.949 | 20 |
| 1988 | 13.8 | 25 |
| 1987 | 15.37 | 19 |
| 1986 | 16.749 | 16 |