1997

6.1

1998

5.7

1999

5.6

1984

5.5

2001

6.7

1972

2.0

1967

5.7

1997

6.3

1998

6.8

1998

7.1

2006

4.8

1988

6.6

1997

7.1

1998

7.1

1931

5.5

1971

0.0

1980

5.2

1952

5.8

2016

5.0

1958

5.9