1999

4.8

1986

5.5

1990

5.8

2004

6.0

1988

4.4

1992

4.1

2005

4.6

1937

3.5

2014

4.4

1937

3.3

1977

5.6

2008

6.6

1981

7.4

1996

6.1

2017

4.8

2001

7.0

2001

6.9

1986

7.1

1942

6.5

1974

5.7