1998

6.7

1997

6.2

1987

4.2

2000

6.6

1989

6.0

1991

6.0

1995

6.2

1993

5.4

1990

5.5

1995

4.7

1992

3.5

1973

7.3

1996

5.3

2013

6.1

2012

7.0

1985

1.0

1988

5.0

1971

4.0

1993

0.0

1992

0.0