1981

6.2

2018

7.5

1985

5.3

1955

7.2

2004

6.6

1984

7.1

1984

7.4

2011

6.6

2007

6.4

1995

7.3

1994

6.6

1987

6.5

1978

7.0

2000

6.3

2010

6.1

1990

6.7

1988

7.8

2003

7.1

1989

7.8

1973

6.5