1995

7.2

1999

8.2

2003

7.1

2003

6.7

1957

8.1

1982

7.4

2001

7.2

1986

7.1

1989

5.7

1991

7.0

1996

7.3

1998

6.4

2002

6.3

1994

6.8

2001

6.7

1972

5.4

1999

5.6

1987

7.7

2000

5.7

2008

6.6