1971

6.8

2014

6.3

2020

7.0

1969

5.1

2009

8.0

1998

5.5

1971

7.5

1948

8.0

1993

7.4

1972

6.4

1973

6.2

1952

7.8

2002

7.1

1961

7.9

1968

6.8

1969

6.5

2002

5.8

1990

6.1

1972

7.2

2006

7.6