| 时间 | 值 （%） | 世界排名 |
|---|---|---|
| 2016 | 1.107 | 108 |
| 2015 | 2.336 | 86 |
| 2014 | 2.725 | 83 |
| 2013 | 2.85 | 98 |
| 2012 | 2.85 | 105 |
| 2011 | 2.695 | 105 |
| 2010 | 3.683 | 81 |
| 2009 | 4.85 | 76 |
| 2008 | 7.642 | 52 |
| 2007 | 6.458 | 61 |
| 2006 | 4.543 | 81 |
| 2005 | 3.954 | 83 |
| 2004 | 4.242 | 75 |
| 2003 | 5.162 | 69 |
| 2002 | 5.188 | 73 |
| 2001 | 4.833 | 97 |
| 2000 | 4.917 | 103 |
| 1999 | 7.454 | 77 |
| 1998 | 10.733 | 54 |
| 1997 | 11.813 | 53 |
| 1996 | 12.733 | 52 |
| 1995 | 13.342 | 47 |
| 1994 | 8.425 | 65 |
| 1993 | 8.063 | 64 |
| 1992 | 10.625 | 48 |
| 1991 | 13 | 38 |
| 1990 | 13 | 35 |
| 1989 | 12.817 | 36 |
| 1988 | 9.583 | 45 |
| 1987 | 7 | 64 |
| 1986 | 10.042 | 39 |