1970

7.0

2007

6.2

1997

7.1

1987

7.3

1957

5.0

1939

7.6

2007

6.1

1990

4.7

2014

5.4

1986

6.3

1995

6.6

1967

7.6

2001

6.8

2003

5.6

1998

6.4

2005

7.4

2001

5.9

2006

7.0

2003

7.2

2020

1.0