| 时间 | 值 （%） | 世界排名 |
|---|---|---|
| 2016 | 32.35 | 74 |
| 2015 | 32.76 | 75 |
| 2014 | 33.47 | 79 |
| 2013 | 34.18 | 81 |
| 2012 | 34.92 | 82 |
| 2011 | 35.75 | 84 |
| 2010 | 36.75 | 84 |
| 2009 | 37.4 | 83 |
| 2008 | 38.11 | 81 |
| 2007 | 38.88 | 79 |
| 2006 | 39.62 | 78 |
| 2005 | 40.21 | 76 |
| 2004 | 41.25 | 76 |
| 2003 | 42.32 | 74 |
| 2002 | 43.47 | 74 |
| 2001 | 44.69 | 76 |
| 2000 | 45.77 | 77 |
| 1999 | 47.17 | 78 |
| 1998 | 48.51 | 79 |
| 1997 | 49.76 | 79 |
| 1996 | 50.84 | 79 |
| 1995 | 51.66 | 79 |
| 1994 | 52.6 | 77 |
| 1993 | 53.36 | 77 |
| 1992 | 54.01 | 77 |
| 1991 | 54.64 | 79 |
| 1990 | 55.21 | 79 |
| 1989 | 56.46 | 78 |
| 1988 | 58.03 | 78 |
| 1987 | 59.98 | 80 |
| 1986 | 62.23 | 84 |