1999

8.2

2003

7.1

2003

6.7

1939

7.6

1988

5.6

2003

6.3

2000

6.4

1995

7.3

2001

7.2

1987

7.7

2001

5.1

1989

6.9

1951

7.2

1992

5.6

2006

5.8

1985

6.2

2007

6.2

2001

7.5

1993

6.1

2004

8.1