1937

7.9

1997

7.6

1996

7.3

1986

7.6

2006

5.6

1995

8.4

1972

6.4

1999

7.4

1971

7.4

2004

7.2

1951

7.7

1958

7.4

1987

6.5

1993

5.6

2005

7.0

2001

5.8

2002

7.6

1968

7.6

2014

5.5

1996

3.9