1989

5.8

1964

6.6

2004

6.5

2009

6.1

1991

8.1

1987

6.5

2001

6.2

2007

6.7

2019

5.7

1989

5.7

1985

6.6

1997

6.3

1996

5.9

1973

5.7

2015

6.0

2016

7.8

2017

7.6

1985

6.2

1979

6.7

1995

5.8