2004

5.2

2000

6.4

1992

7.0

1992

6.6

1981

6.5

1980

7.0

2001

5.9

1971

4.2

1977

3.8

1970

7.6

1982

3.0

1999

3.8

1994

7.3

1941

7.1

1963

7.5

1991

7.1

2002

6.4

1987

5.6

2013

5.3

2004

5.6