| 时间 | 值 （%） | 世界排名 |
|---|---|---|
| 2016 | 85.16 | 32 |
| 2015 | 82.91 | 39 |
| 2014 | 81.41 | 51 |
| 2013 | 78.71 | 59 |
| 2012 | 76.83 | 64 |
| 2011 | 75.51 | 68 |
| 2010 | 70.47 | 68 |
| 2009 | 65.02 | 72 |
| 2008 | 71.05 | 81 |
| 2007 | 71.25 | 77 |
| 2006 | 68.95 | 78 |
| 2005 | 62.42 | 87 |
| 2004 | 64.58 | 80 |
| 2003 | 56.1 | 92 |
| 2002 | 48.54 | 115 |
| 2001 | 45.24 | 126 |
| 2000 | 46.99 | 121 |
| 1999 | 43.16 | 126 |
| 1998 | 43.17 | 126 |
| 1997 | 42.77 | 124 |
| 1996 | 38.5 | 136 |
| 1995 | 36.55 | 144 |
| 1994 | 36.03 | 134 |
| 1993 | 35.73 | 114 |
| 1992 | 35.02 | 116 |
| 1991 | 37.65 | 98 |
| 1990 | 39.24 | 101 |