1992

0.0

1987

6.5

2007

7.1

2007

5.0

1999

6.0

1988

6.5

1993

8.1

2006

6.9

1994

7.4

1991

8.3

1996

5.4

2004

7.2

1967

7.7

1956

7.2

1954

6.0

1983

6.1

1990

6.7

1933

6.9

1981

6.4

1973

5.4