1990

6.5

2006

5.9

1954

7.2

1968

6.1

2016

5.2

2014

7.0

1947

7.6

2004

7.5

1975

7.8

1990

7.4

1992

6.8

1996

7.9

1960

8.2

1991

7.5

1993

7.5

2002

6.9

1990

7.5

1986

7.6

1995

8.4

2001

7.7