1968

6.9

1999

7.4

2012

6.2

1955

7.2

1985

6.2

1961

6.9

2009

7.4

1985

6.2

1980

6.6

1957

7.6

1986

5.8

5.0

2017

6.0

1931

7.1

1995

6.3

1990

5.3

1983

5.5

2005

5.7

1988

5.9