1969

6.6

1975

7.2

2011

7.1

2016

5.9

2015

6.3

2018

5.3

2011

5.5

2014

4.9

2017

7.6

1964

7.0

1970

6.4

2016

4.9

1971

7.4

2004

7.4

2009

7.4

1989

6.5

1982

6.9

2014

6.2

1988

6.3

1992

6.9