1983

6.3

1972

7.1

2004

7.3

1999

6.9

1987

4.1

1992

6.7

1987

7.1

1997

8.4

2002

6.6

1989

7.8

1990

7.5

2008

6.0

1999

7.4

2014

5.6

2018

0.0

1960

8.4

1984

5.0

1975

7.8

2017

7.4

1981

7.9