| 时间 | 值 （%） | 世界排名 |
|---|---|---|
| 2016 | 2.97 | 21 |
| 2015 | 2.75 | 27 |
| 2014 | 2.7 | 32 |
| 2013 | 2.56 | 32 |
| 2012 | 2.72 | 29 |
| 2009 | 3.14 | 33 |
| 2008 | 3.06 | 26 |
| 2006 | 2.69 | 35 |
| 2005 | 3.05 | 25 |
| 2004 | 3.84 | 18 |
| 2003 | 4 | 18 |
| 2002 | 2.74 | 39 |
| 2001 | 4 | 22 |
| 2000 | 2.93 | 37 |
| 1999 | 2.27 | 53 |
| 1998 | 1.86 | 65 |
| 1997 | 2.97 | 39 |
| 1996 | 2.63 | 43 |
| 1995 | 2.26 | 61 |
| 1994 | 2.24 | 62 |
| 1993 | 2.41 | 59 |
| 1992 | 2.69 | 49 |
| 1991 | 2.73 | 53 |
| 1990 | 3.94 | 29 |
| 1989 | 3.96 | 31 |
| 1988 | 4.49 | 25 |
| 1987 | 4.81 | 21 |
| 1986 | 5.29 | 17 |