1955

7.5

1994

8.7

2008

8.5

1977

8.2

1994

8.5

1989

7.8

2013

7.9

1980

8.4

2017

6.8

2003

8.0

2016

7.9

2006

7.8

1975

8.4

2015

7.5

1985

8.3

2019

8.1

2018

8.2

2011

7.3

2007

7.3

1997

7.9