| 时间 | 值 （%） | 世界排名 |
|---|---|---|
| 2016 | 78.53 | 71 |
| 2015 | 65.16 | 121 |
| 2014 | 73.33 | 118 |
| 2013 | 78.27 | 110 |
| 2012 | 67.88 | 132 |
| 2011 | 48.79 | 169 |
| 2010 | 57.65 | 147 |
| 2009 | 51.68 | 152 |
| 2008 | 61.97 | 144 |
| 2007 | 56.44 | 154 |
| 2006 | 54.36 | 157 |
| 2005 | 57.45 | 146 |
| 2004 | 51.47 | 152 |
| 2003 | 50.84 | 153 |
| 2002 | 41.9 | 161 |
| 2001 | 67.12 | 108 |
| 2000 | 60.94 | 120 |
| 1999 | 71.32 | 91 |
| 1998 | 70.88 | 98 |
| 1997 | 54.94 | 127 |
| 1996 | 54.7 | 119 |
| 1995 | 78.46 | 74 |
| 1994 | 91.38 | 51 |
| 1993 | 48.35 | 121 |
| 1992 | 65.66 | 79 |
| 1991 | 52.58 | 101 |
| 1990 | 57.2 | 92 |
| 1989 | 53.3 | 86 |
| 1988 | 55.87 | 75 |
| 1987 | 53.26 | 76 |
| 1986 | 47.96 | 89 |