1963

6.6

1978

7.6

1981

6.1

2008

5.5

1993

6.2

1980

7.7

2016

0.0

2000

7.6

1998

8.3

1959

7.8

2001

7.8

1953

7.3

1976

7.1

2004

7.4

2015

6.3

1984

6.5

2006

6.6

1980

6.4

2015

6.9

1988

6.8