1981

6.4

2011

5.9

1997

6.5

1942

10.0

2004

6.7

1990

7.8

2003

6.7

2009

4.5

1996

7.3

2003

5.1

2001

7.6

2000

6.7

2001

5.6

1989

0.0

1987

0.0

1994

0.0

1989

5.1

2002

4.2

1954

6.0

2014

6.3