1982

4.7

2001

6.1

1993

5.0

1997

6.8

1975

5.8

1996

7.0

1976

6.8

1982

5.9

1968

5.4

2004

5.5

2016

0.0

1975

5.6

1976

5.9

2007

6.7

2002

6.7

2006

6.2

1998

6.4

1997

7.6

1999

6.8

1962

7.3