1974

5.8

1975

6.8

2007

7.3

2008

6.1

1987

6.1

2002

5.7

1991

5.1

1993

6.2

1979

6.7

1976

4.8

2002

6.1

1984

4.8

2019

6.9

2019

6.4

2009

7.2

1998

5.0

1993

7.3

1970

7.5

2009

6.7

2003

5.5