1957

7.1

1990

6.4

1987

7.1

1931

5.8

2012

7.7

1988

6.3

1997

6.1

2017

6.2

1998

5.1

2020

5.5

2016

6.3

2019

6.7

2009

5.6

2005

5.4

2017

6.5

1990

6.3

2018

6.1

2001

6.1

1994

6.6

2017

6.9