1964

7.4

1971

7.8

1988

5.8

1962

6.9

1974

5.8

1985

6.7

1975

7.3

1985

4.3

1972

7.5

1989

7.5

2003

8.6

1999

6.9

2005

7.3

2000

8.5

1993

6.8

1983

7.6

1969

7.2

1995

5.0

1989

6.1

2003

7.5