1984

7.1

2006

6.2

1989

6.5

1963

6.9

2009

5.3

2004

6.2

1985

6.2

2001

5.2

1986

6.8

2002

6.0

1994

5.7

1978

6.9

1994

6.6

1988

7.3

1988

5.7

1988

5.2

1993

5.8

2015

7.8

2011

6.5

2008

5.6