1991

7.1

2003

5.3

1958

7.5

2003

7.4

1994

7.5

1942

3.0

2002

6.4

1984

6.8

1986

6.3

2005

6.2

1987

7.3

1988

6.6

2006

3.1

2007

6.6

2009

7.2

1974

5.6

1934

6.5

1994

6.8

1982

6.7

2014

6.0