2002

6.8

1975

5.6

2000

5.4

2005

5.9

1976

6.6

1983

5.4

2014

6.3

1992

7.1

2013

6.7

1986

6.1

1974

7.0

1957

5.7

2006

6.2

1992

5.9

1986

6.6

1982

4.6

2000

7.0

1980

6.4

1963

6.5

1974

6.8