1962

7.9

2007

6.2

2004

8.0

1996

7.0

1975

7.8

1987

7.5

1992

7.3

2005

7.1

2005

6.3

2006

6.6

1999

6.5

1929

7.4

2015

7.5

1999

5.6

2000

6.1

1989

6.9

1991

6.3

2004

6.7

1993

5.5

1990

6.8