1962

5.1

1985

7.7

1987

7.1

2006

6.8

1999

7.4

1979

7.8

1967

6.7

1973

6.9

1994

6.7

1977

6.2

2001

5.8

2000

6.4

2007

5.2

1981

7.0

1989

6.7

2008

5.9

1959

6.3

2006

5.6

2001

4.7

2016

6.2