| 时间 | 值 （%） | 世界排名 |
|---|---|---|
| 2016 | 3.53 | 41 |
| 2015 | 6.36 | 32 |
| 2014 | 6.39 | 32 |
| 2013 | 6.41 | 37 |
| 2012 | 4.28 | 80 |
| 2011 | 5.36 | 78 |
| 2010 | 5.13 | 62 |
| 2009 | 4.81 | 61 |
| 2008 | 9.78 | 80 |
| 2007 | 6.41 | 70 |
| 2006 | 13.11 | 11 |
| 2005 | 10.45 | 30 |
| 2004 | 6.24 | 59 |
| 2003 | 6.59 | 54 |
| 2002 | 11.88 | 28 |
| 2001 | 11.5 | 24 |
| 2000 | 3.72 | 82 |
| 1999 | 20.49 | 19 |
| 1998 | 58.39 | 6 |
| 1997 | 6.23 | 76 |
| 1996 | 7.97 | 74 |
| 1995 | 9.43 | 79 |
| 1994 | 8.52 | 85 |
| 1993 | 9.69 | 71 |
| 1992 | 7.53 | 74 |
| 1991 | 9.42 | 68 |
| 1990 | 7.81 | 72 |
| 1989 | 6.42 | 75 |
| 1988 | 8.04 | 61 |
| 1987 | 9.28 | 51 |
| 1986 | 5.83 | 65 |