| 时间 | 值 （%） | 世界排名 |
|---|---|---|
| 2016 | 87.3 | 29 |
| 2015 | 87.14 | 34 |
| 2014 | 91.14 | 38 |
| 2013 | 88.04 | 47 |
| 2012 | 88.22 | 48 |
| 2011 | 90.72 | 47 |
| 2010 | 81.72 | 52 |
| 2009 | 72.31 | 58 |
| 2008 | 90.1 | 50 |
| 2007 | 87.93 | 48 |
| 2006 | 82.91 | 54 |
| 2005 | 84.36 | 47 |
| 2004 | 76.9 | 57 |
| 2003 | 73.37 | 53 |
| 2002 | 73.34 | 59 |
| 2001 | 76.29 | 53 |
| 2000 | 75.84 | 58 |
| 1999 | 86.56 | 33 |
| 1998 | 85.38 | 35 |
| 1997 | 79.2 | 42 |
| 1996 | 79.61 | 41 |
| 1995 | 66.11 | 61 |
| 1994 | 78.44 | 31 |