1968

7.0

1990

0.0

1992

6.6

1983

7.4

2002

6.7

1998

7.2

2000

6.5

2004

6.1

2006

5.5

2007

5.6

1987

7.5

1990

6.1

1985

6.6

2009

6.6

2003

6.0

1993

6.9

0.0

1942

0.0

1973

6.4

1976

0.0