1985

5.3

1978

3.2

1960

4.7

2009

7.5

1994

3.0

2001

7.2

1990

6.3

1998

6.4

2008

6.0

1982

7.5

1996

6.9

1997

7.2

2002

6.4

1968

6.9

1965

4.6

1970

4.5

1999

5.6

1977

3.6

1955

6.0

1977

7.3