1982

6.5

1989

7.4

2013

5.8

1975

6.2

1994

6.0

1997

4.0

1973

4.8

1990

7.4

1975

7.5

1983

5.5

1989

7.1

1976

6.4

1998

7.0

1980

6.2

1997

6.0

1993

4.8

1980

4.4