1983

4.5

1985

6.2

1990

6.1

2011

7.5

1988

6.1

1997

6.1

1966

7.4

2020

5.8

2001

5.2

2015

6.3

2015

6.4

1987

4.6

1989

5.6

1961

7.4

1985

6.2

2016

4.9

1937

7.1

2010

5.2

1988

5.9

1999

6.1