1991

6.2

1990

6.7

1993

5.5

2006

6.9

2008

6.2

1996

6.8

1942

7.0

2002

10.0

1987

7.7

1998

7.0

2014

5.3

2007

6.5

1986

6.8

1967

7.3

1985

7.5

1994

6.2

1976

7.3

2006

6.1

1998

6.9

2004

6.4