| 时间 | 值 （%） | 世界排名 |
|---|---|---|
| 2016 | 73.78 | 59 |
| 2015 | 74.02 | 57 |
| 2014 | 74.31 | 54 |
| 2013 | 74.61 | 53 |
| 2012 | 74.95 | 53 |
| 2011 | 75.29 | 46 |
| 2010 | 75.61 | 43 |
| 2009 | 75.61 | 40 |
| 2008 | 75.66 | 43 |
| 2007 | 75.81 | 43 |
| 2006 | 76.06 | 42 |
| 2005 | 76.34 | 39 |
| 2004 | 76.36 | 40 |
| 2003 | 76.42 | 41 |
| 2002 | 76.6 | 42 |
| 2001 | 76.91 | 45 |
| 2000 | 77.63 | 41 |
| 1999 | 77.53 | 40 |
| 1998 | 77.4 | 41 |
| 1997 | 77.3 | 42 |
| 1996 | 77.28 | 45 |
| 1995 | 77.38 | 44 |
| 1994 | 77.36 | 47 |
| 1993 | 77.62 | 49 |
| 1992 | 77.99 | 48 |
| 1991 | 78.43 | 46 |