1941

5.5

1964

7.4

1985

6.1

2011

5.8

1969

7.1

2005

7.5

2009

7.1

1989

6.2

2004

7.9

1980

7.2

1985

6.2

1944

7.4

1989

5.2

1988

7.3

2014

6.1

2001

6.0

2001

6.6

2014

6.5

1987

7.8

2000

6.4