| 时间 | 值 （%） | 世界排名 |
|---|---|---|
| 2016 | 75.19 | 87 |
| 2015 | 75.33 | 87 |
| 2014 | 75.48 | 86 |
| 2013 | 75.81 | 84 |
| 2012 | 76.17 | 80 |
| 2011 | 76.53 | 77 |
| 2010 | 76.85 | 71 |
| 2009 | 76.94 | 70 |
| 2008 | 77.07 | 70 |
| 2007 | 77.32 | 67 |
| 2006 | 77.66 | 64 |
| 2005 | 78.07 | 63 |
| 2004 | 78.2 | 64 |
| 2003 | 78.39 | 64 |
| 2002 | 78.7 | 66 |
| 2001 | 79.14 | 66 |
| 2000 | 80.01 | 61 |
| 1999 | 80.08 | 61 |
| 1998 | 80.13 | 62 |
| 1997 | 80.2 | 63 |
| 1996 | 80.36 | 64 |
| 1995 | 80.64 | 64 |
| 1994 | 80.83 | 59 |
| 1993 | 81.12 | 57 |
| 1992 | 81.53 | 53 |
| 1991 | 81.99 | 52 |
| 1990 | 82.51 | 50 |