1960

7.5

1987

6.9

2014

8.5

1976

8.1

1972

8.7

1991

8.3

1995

8.4

1968

8.1

1968

8.3

1997

7.4

1995

7.6

2000

8.2

2008

7.8

2019

8.1

1978

8.0

2015

7.8

1979

8.2

2001

7.9

1986

7.1

2000

7.4