| 时间 | 值 （%） | 世界排名 |
|---|---|---|
| 2015 | 84.32 | 80 |
| 2014 | 80.06 | 100 |
| 2013 | 84.6 | 94 |
| 2012 | 79.1 | 108 |
| 2011 | 76.21 | 119 |
| 2010 | 67.9 | 131 |
| 2009 | 56.12 | 143 |
| 2008 | 59.45 | 146 |
| 2007 | 65.77 | 134 |
| 2006 | 57.86 | 148 |
| 2005 | 62.2 | 141 |
| 2004 | 70.81 | 121 |
| 2003 | 62.31 | 129 |
| 2002 | 64.92 | 118 |
| 2001 | 64.67 | 114 |
| 2000 | 60.39 | 122 |
| 1999 | 59.77 | 115 |
| 1998 | 56.25 | 117 |
| 1997 | 58.27 | 117 |
| 1996 | 63.82 | 102 |
| 1995 | 69.23 | 93 |
| 1994 | 66.65 | 89 |