1975

6.4

2009

5.9

2018

6.0

2017

6.5

2015

6.5

2017

6.9

2006

6.1

2013

6.6

2011

6.8

1963

6.8

1990

5.7

2017

6.6

2003

6.8

2020

5.8

1993

6.5

1988

6.5

2011

6.6

2002

6.2

2019

6.6

2001

6.8