1987

7.3

2004

7.3

1985

7.2

1961

5.7

2009

4.6

2006

7.1

1945

7.7

2005

6.9

1939

7.6

1998

7.4

1998

6.4

2001

5.9

2006

7.0

2003

7.2

1959

5.6

1944

4.3

2007

6.6

1966

6.7

1960

5.4

2015

5.8