1998

6.3

1997

5.2

1975

5.5

1957

5.5

1964

6.3

2006

6.0

1986

6.7

1978

4.7

1990

2.7

2005

6.5

1985

7.2

2017

9.5

1995

5.0

1995

6.8

2016

6.1

2003

7.0

2009

5.7

2018

5.1

1981

6.4

2013

3.3