1991

7.2

0.0

2004

5.6

1970

5.5

1985

6.4

2001

6.1

1999

7.3

1990

6.7

2000

6.4

2003

6.1

2001

6.3

2007

6.7

2003

5.1

2002

6.7

1996

7.0

2006

7.4

1967

7.5

1990

7.0

1993

6.2

1999

6.4