1996

6.4

2000

8.2

2018

6.3

1979

7.8

2001

7.8

1980

7.3

1997

6.6

1999

6.3

2002

6.0

2017

5.8

1999

7.1

1987

6.9

2004

7.5

1975

7.8

1920

0.0

1977

0.0

1985

5.2

1987

5.7

2002

4.4

1996

7.0