| 时间 | 值 （%） | 世界排名 |
|---|---|---|
| 2016 | 89.65 | 25 |
| 2015 | 87 | 30 |
| 2014 | 67.14 | 52 |
| 2013 | 63 | 51 |
| 2012 | 56.03 | 64 |
| 2011 | 50.76 | 72 |
| 2010 | 58.12 | 63 |
| 2009 | 60.42 | 63 |
| 2008 | 43.85 | 86 |
| 2007 | 52.98 | 73 |
| 2006 | 49.71 | 69 |
| 2005 | 48.68 | 68 |
| 2004 | 47.81 | 69 |
| 2003 | 53.38 | 60 |
| 2002 | 61.48 | 45 |
| 2001 | 62.37 | 42 |
| 2000 | 44.48 | 61 |
| 1999 | 57.6 | 40 |
| 1998 | 62.5 | 33 |
| 1997 | 52.52 | 44 |
| 1996 | 59.61 | 39 |
| 1995 | 62.86 | 31 |
| 1994 | 68.62 | 22 |
| 1993 | 64.83 | 28 |
| 1992 | 53.99 | 40 |
| 1991 | 55.55 | 32 |
| 1990 | 50.76 | 41 |
| 1989 | 60.34 | 29 |
| 1988 | 56.91 | 31 |
| 1987 | 68.85 | 18 |
| 1986 | 68.34 | 18 |