| 时间 | 值 （%） | 世界排名 |
|---|---|---|
| 2016 | 50.4 | 38 |
| 2015 | 49.68 | 40 |
| 2014 | 47.99 | 47 |
| 2013 | 52.54 | 33 |
| 2012 | 52.75 | 35 |
| 2011 | 52.81 | 34 |
| 2010 | 40.12 | 76 |
| 2009 | 46.49 | 49 |
| 2008 | 50.03 | 42 |
| 2007 | 51.29 | 41 |
| 2006 | 41.36 | 78 |
| 2005 | 44.19 | 61 |
| 2004 | 44.84 | 56 |
| 2003 | 42.14 | 67 |
| 2002 | 39.46 | 87 |
| 2001 | 40.09 | 87 |
| 2000 | 37.17 | 107 |
| 1999 | 34.05 | 125 |
| 1998 | 36.78 | 113 |
| 1997 | 36.42 | 118 |
| 1996 | 36.57 | 116 |
| 1995 | 36.59 | 123 |
| 1994 | 37.26 | 118 |
| 1993 | 36.28 | 127 |
| 1992 | 35.15 | 138 |
| 1991 | 32.28 | 146 |