1961

7.5

2004

6.3

2003

7.4

1994

7.4

1950

8.0

2005

6.9

1962

5.9

1996

7.0

1992

6.1

1991

6.3

2002

6.0

2008

5.5

1968

6.9

1985

6.0

2014

6.3

2001

4.5

1949

6.8

1990

5.7

1939

3.7

2000

0.0