2005

7.2

2000

8.2

1959

7.8

1976

8.1

1985

6.9

1972

8.7

1974

8.6

1990

7.4

1989

6.9

2006

6.9

2000

6.0

1988

6.0

1955

7.2

2010

7.2

2020

6.5

1993

5.3

1949

7.1

2016

5.9

1938

4.9

2009

6.2