| 时间 | 值 （%） | 世界排名 |
|---|---|---|
| 2016 | 0.57 | 96 |
| 2015 | 0.6 | 94 |
| 2014 | 0.64 | 92 |
| 2013 | 0.69 | 92 |
| 2012 | 0.74 | 89 |
| 2011 | 0.81 | 87 |
| 2010 | 0.87 | 85 |
| 2009 | 0.93 | 84 |
| 2008 | 0.98 | 85 |
| 2007 | 1.03 | 79 |
| 2006 | 1.08 | 81 |
| 2005 | 1.12 | 76 |
| 2004 | 1.16 | 75 |
| 2003 | 1.2 | 72 |
| 2002 | 1.24 | 74 |
| 2001 | 1.39 | 63 |
| 2000 | 1.48 | 61 |
| 1999 | 1.52 | 65 |
| 1998 | 1.55 | 65 |
| 1997 | 1.58 | 64 |
| 1996 | 1.61 | 65 |
| 1995 | 1.64 | 61 |
| 1994 | 1.66 | 62 |
| 1993 | 1.69 | 62 |
| 1992 | 1.72 | 61 |
| 1991 | 1.73 | 62 |
| 1990 | 1.75 | 60 |
| 1989 | 1.78 | 64 |
| 1988 | 1.82 | 61 |
| 1987 | 1.86 | 61 |
| 1986 | 1.9 | 61 |