1994

7.4

2006

7.6

2014

6.7

1993

6.3

2000

7.0

1987

7.6

1986

7.4

2002

6.7

1988

7.4

2008

6.5

2007

6.9

2005

7.7

1996

7.3

2004

6.8

2006

6.4

2014

5.2

2015

6.1

1996

6.1

2007

6.7

1998

7.2