1987

5.7

2007

6.8

1986

7.2

10.0

2003

5.7

2003

6.9

2006

6.1

1968

6.9

2017

6.1

2007

5.9

2002

6.0

1994

6.2

1976

7.3

1989

5.0

1961

6.0

1993

7.0

1971

0.0

2015

6.0

2012

10.0

1985

6.5