1952

6.8

1972

6.0

1950

6.8

1985

6.0

1980

5.9

1976

4.7

1953

6.6

1985

5.0

2016

6.0

1985

5.9

1987

6.3

1999

6.5

2002

6.7

2003

6.6

2009

6.2

2017

6.6

2007

7.5

2001

7.0

2007

6.7

1978

7.2