1985

8.1

1989

6.5

2006

7.0

2000

7.7

1996

9.0

1971

6.0

2008

6.9

2002

6.1

1990

5.4

1959

0.0

1992

0.0

1986

8.9

1991

9.5

1976

8.0

2016

6.9

2012

8.6

2014

7.3

1983

8.8

1972

0.0

1996

7.0

1975

0.0

1988

6.2

1990

7.7

1989

8.0

1977

0.0

2004

6.6

2001

7.4

1986

0.0