1990

6.2

1992

6.2

2015

6.0

2001

7.8

1993

6.3

1991

7.2

1999

7.1

2008

6.6

1995

6.2

1988

6.3

1986

5.8

1978

7.2

1998

6.1

1976

7.6

1946

7.6

1987

7.3

1989

7.0

1992

6.7

1998

6.6

1978

7.6