2004

5.3

2000

6.4

1990

6.5

1977

6.4

2000

7.2

1968

7.1

1976

6.0

1974

6.9

1964

6.7

1988

6.8

2014

7.3

1975

6.4

1969

5.1

1970

6.3

1998

6.1

1972

6.2

1981

7.0

1967

6.4

1994

6.7

1970

5.0

1988

10.0