| 时间 | 值 （%） | 世界排名 |
|---|---|---|
| 2014 | 44.92 | 91 |
| 2013 | 52.33 | 76 |
| 2012 | 52.91 | 67 |
| 2011 | 50.11 | 73 |
| 2010 | 49.33 | 80 |
| 2009 | 52.94 | 73 |
| 2008 | 44.91 | 83 |
| 2007 | 47.84 | 81 |
| 2006 | 41.67 | 88 |
| 2005 | 33.58 | 102 |
| 2004 | 30.94 | 108 |
| 2003 | 27.14 | 114 |
| 2002 | 30.62 | 102 |
| 2001 | 32.01 | 98 |
| 2000 | 32.17 | 88 |
| 1999 | 33.78 | 86 |
| 1998 | 35.01 | 81 |
| 1997 | 37.66 | 69 |
| 1996 | 36.44 | 70 |
| 1995 | 30.57 | 86 |
| 1994 | 30.1 | 86 |
| 1993 | 34.65 | 74 |
| 1992 | 33.9 | 72 |
| 1991 | 35.29 | 65 |
| 1990 | 35.16 | 61 |
| 1989 | 34.06 | 65 |
| 1988 | 31.07 | 69 |
| 1987 | 33.05 | 63 |
| 1986 | 36.11 | 57 |