1952

7.3

1973

6.1

1985

7.7

1985

7.2

1992

7.5

1988

7.0

2008

6.5

2005

6.2

2006

5.5

2006

6.5

1998

6.9

1997

5.6

1964

7.4

1975

7.2

2008

6.2

1978

6.1

2016

0.0

1967

6.9

2005

7.1

1980

6.7