| 时间 | 值 （%） | 世界排名 |
|---|---|---|
| 2016 | 1.03 | 72 |
| 2015 | 1.05 | 71 |
| 2014 | 1.08 | 69 |
| 2013 | 1.17 | 67 |
| 2012 | 1.35 | 59 |
| 2011 | 1.54 | 53 |
| 2010 | 1.76 | 53 |
| 2009 | 1.96 | 43 |
| 2008 | 2.11 | 35 |
| 2007 | 2.17 | 37 |
| 2006 | 2.17 | 34 |
| 2005 | 2.14 | 34 |
| 2004 | 2.14 | 36 |
| 2003 | 2.13 | 37 |
| 2002 | 1.96 | 44 |
| 2001 | 1.4 | 62 |
| 2000 | 1.46 | 62 |
| 1999 | 1.5 | 66 |
| 1998 | 1.56 | 64 |
| 1997 | 1.63 | 61 |
| 1996 | 1.7 | 61 |
| 1995 | 1.78 | 56 |
| 1994 | 1.84 | 55 |
| 1993 | 1.64 | 66 |
| 1992 | 0.95 | 97 |
| 1991 | 0.88 | 99 |
| 1990 | 0.81 | 105 |
| 1989 | 0.73 | 110 |
| 1988 | 0.57 | 115 |
| 1987 | 0.32 | 127 |
| 1986 | 0.01 | 142 |