1982

6.0

1988

5.4

2008

5.1

2013

5.2

1992

4.7

2000

5.2

1980

4.8

1973

5.2

2001

3.5

2002

3.7

1999

3.0

1989

3.7

1980

5.1

1975

5.8

1978

5.0

1998

2.3

1975

2.4

1974

3.8

1971

6.0

1990

3.5