1990

5.9

2020

6.3

1976

4.7

1987

4.6

1981

5.9

1972

5.8

1973

3.1

1981

3.3

1965

4.6

2005

5.1

1980

5.6

2013

3.2

2007

3.8

2001

4.7

1953

5.9

1987

5.2

1955

4.2

1970

3.2

1978

4.1

2009

5.3