| 时间 | 值 （%） | 世界排名 |
|---|---|---|
| 2016 | 11.04 | 49 |
| 2015 | 18.96 | 24 |
| 2014 | 15.43 | 32 |
| 2013 | 18.32 | 31 |
| 2012 | 15.39 | 45 |
| 2011 | 12.62 | 67 |
| 2010 | 21.67 | 35 |
| 2009 | 14.34 | 65 |
| 2008 | 7.33 | 131 |
| 2007 | 18.48 | 81 |
| 2006 | 8.42 | 140 |
| 2005 | 9.78 | 117 |
| 2004 | 17.22 | 62 |
| 2003 | 12.64 | 85 |
| 2002 | 13.3 | 74 |
| 2001 | 4.11 | 141 |
| 2000 | 9.38 | 105 |
| 1999 | 18.81 | 51 |
| 1998 | 32.15 | 15 |
| 1997 | 52.54 | 13 |
| 1996 | 52.53 | 9 |
| 1995 | 35.07 | 32 |
| 1994 | 65.9 | 18 |
| 1993 | 25.2 | 47 |
| 1992 | 20.07 | 55 |
| 1991 | 1519.64 | 2 |
| 1990 | 7677.83 | 1 |
| 1989 | 2700.19 | 1 |
| 1988 | 12513.14 | 1 |
| 1987 | 544.24 | 1 |
| 1986 | 234.5 | 2 |