| 时间 | 值 （%） | 世界排名 |
|---|---|---|
| 2016 | 63.35 | 67 |
| 2015 | 54.27 | 98 |
| 2014 | 65.91 | 80 |
| 2013 | 57.3 | 102 |
| 2012 | 73.78 | 75 |
| 2011 | 69.83 | 79 |
| 2010 | 60.73 | 93 |
| 2009 | 45.77 | 134 |
| 2008 | 59.97 | 112 |
| 2007 | 58.55 | 114 |
| 2006 | 67.85 | 79 |
| 2005 | 56.95 | 110 |
| 2004 | 41.57 | 150 |
| 2003 | 36.24 | 157 |
| 2002 | 46.65 | 122 |
| 2001 | 47.01 | 121 |
| 2000 | 42.67 | 132 |
| 1999 | 34.43 | 148 |
| 1998 | 34.27 | 151 |
| 1997 | 34.48 | 149 |
| 1996 | 35.06 | 146 |
| 1995 | 41.16 | 132 |
| 1994 | 36.11 | 133 |
| 1993 | 39.37 | 108 |
| 1992 | 38.28 | 111 |
| 1991 | 47.17 | 80 |
| 1990 | 52.28 | 72 |
| 1989 | 48.68 | 76 |
| 1988 | 46.81 | 79 |
| 1987 | 49.57 | 70 |
| 1986 | 51.02 | 62 |