1997

7.0

2002

6.6

2006

6.2

1966

7.7

1989

6.4

1998

6.6

2000

8.1

1967

7.3

1979

6.9

1995

7.7

1979

7.7

1999

3.6

1993

7.4

1968

7.1

1963

8.1

2001

6.8

1975

7.3

2006

7.1

1996

7.2

1973

3.8