1937

7.4

1980

7.5

2001

7.4

2005

6.7

2018

3.5

2016

6.6

2002

6.6

1989

8.3

1955

7.5

1983

7.2

1979

7.0

1986

7.9

1987

7.3

2000

6.3

1959

8.0

2005

6.9

2000

7.6

2013

5.3

2020

5.5

2015

4.7