| 时间 | 值 （%） | 世界排名 |
|---|---|---|
| 2016 | 75.8 | 45 |
| 2015 | 75.93 | 44 |
| 2014 | 76.1 | 42 |
| 2013 | 76.19 | 42 |
| 2012 | 75.14 | 50 |
| 2011 | 74.69 | 49 |
| 2010 | 74.46 | 50 |
| 2009 | 74.34 | 50 |
| 2008 | 75.42 | 46 |
| 2007 | 76.04 | 42 |
| 2006 | 75.67 | 46 |
| 2005 | 75.87 | 43 |
| 2004 | 75.4 | 49 |
| 2003 | 74.78 | 50 |
| 2002 | 72.12 | 63 |
| 2001 | 77.13 | 44 |
| 2000 | 75.1 | 53 |
| 1999 | 74.22 | 57 |
| 1998 | 72.61 | 69 |
| 1997 | 72.64 | 71 |
| 1996 | 71.44 | 83 |
| 1995 | 70.35 | 87 |
| 1994 | 73.45 | 72 |
| 1993 | 72.94 | 76 |
| 1992 | 72.56 | 77 |
| 1991 | 73.28 | 76 |