1970

4.2

1971

4.4

1968

4.9

1976

3.0

1998

8.0

1983

6.6

1977

5.6

2006

5.2

2007

5.8

2005

3.0

1970

4.1

1993

5.5

1980

5.1

1999

4.0

1976

3.3

1991

4.6

1974

4.0

1975

5.4

1970

5.5

1970

5.0