1996

5.7

1991

0.0

2006

5.4

1990

7.3

1995

8.0

1988

6.7

2005

5.2

1992

7.4

1997

5.9

1979

5.1

1960

6.4

1973

7.5

1994

5.9

1960

7.6

1987

3.8

1995

9.0