1969

2.3

2003

7.3

1971

6.4

1972

7.9

1994

6.6

1985

6.3

1976

6.7

1993

6.2

1999

7.5

1985

6.1

2001

6.4

1942

7.0

1979

6.7

1966

7.8

1961

7.9

1974

6.5

2001

6.1

1965

6.7

1998

7.0

1986

6.8