1988

6.8

1975

6.8

1999

7.3

2016

6.5

1990

7.5

2020

5.5

2018

6.3

2018

6.0

2014

5.8

2008

7.6

1994

6.9

2012

6.2

1995

6.4

2009

6.6

1989

7.1

1994

5.9

1957

7.2

1952

7.9

2009

5.6

2007

6.9