1975

6.1

2009

7.4

1980

6.7

2017

6.9

2016

5.9

1993

5.5

1965

7.1

2006

5.5

1960

7.5

2015

7.0

1983

5.5

2009

8.5

2015

3.6

1985

6.4

1999

6.3

2012

6.0

1998

5.4

2015

5.1

1990

5.9

1992

4.3