2003

8.3

1987

7.1

2007

5.3

2003

7.2

1990

6.7

1984

6.2

1993

5.5

1985

7.8

2015

4.3

1982

4.9

2013

5.2

1999

3.7

2001

6.9

1999

7.1

1980

5.1

1973

3.5

1975

5.8

1973

5.8

1967

5.3

1961

4.6