1980

6.7

1971

6.4

1993

5.5

1987

5.5

2001

6.1

1979

6.2

1985

6.2

1976

6.7

2013

6.6

2004

5.6

1966

6.6

1973

6.5

2013

6.0

1987

6.9

2005

6.3

1951

6.3

1953

5.4

1965

6.7

1997

6.2

1989

6.4