1972

4.0

2018

3.7

2017

6.9

2008

6.8

2006

4.3

2007

6.1

1987

8.0

1988

5.2

1982

7.5

2004

5.7

2017

6.4

1991

7.0

1959

5.6

2011

9.5

2009

6.2

1965

5.6

2021

5.4

1957

7.1

1993

7.5

2006

7.1