| 时间 | 值 （%） | 世界排名 |
|---|---|---|
| 2016 | 85.91 | 28 |
| 2015 | 83.51 | 35 |
| 2014 | 81.31 | 32 |
| 2013 | 81.83 | 29 |
| 2012 | 75.23 | 36 |
| 2011 | 70.48 | 42 |
| 2010 | 67.86 | 49 |
| 2009 | 65.53 | 54 |
| 2008 | 62.69 | 53 |
| 2007 | 65.8 | 48 |
| 2006 | 59.94 | 51 |
| 2005 | 53.81 | 58 |
| 2004 | 50.58 | 60 |
| 2003 | 45.91 | 75 |
| 2002 | 41.05 | 81 |
| 2001 | 40.2 | 79 |
| 2000 | 35.31 | 81 |
| 1999 | 30.39 | 94 |
| 1998 | 25.81 | 99 |
| 1997 | 31.59 | 87 |
| 1996 | 73.25 | 22 |
| 1995 | 67.03 | 28 |
| 1994 | 79.7 | 14 |
| 1993 | 78.97 | 15 |
| 1992 | 76.39 | 17 |
| 1991 | 74.53 | 16 |