1995

4.6

1993

6.4

1987

5.3

1985

6.8

2019

6.7

2017

6.9

1983

7.2

2019

6.5

2020

6.5

1994

6.1

1996

7.1

1989

5.9

2010

5.2

2019

7.0

1970

6.1

2012

5.4

2007

5.5

1971

6.0

2013

7.6

1953

4.8