1999

4.2

1998

6.0

1998

6.6

1985

5.3

2001

6.7

1963

7.9

1989

7.9

2001

6.4

2002

7.3

1984

6.1

2004

7.7

2007

6.2

1990

7.4

2006

6.5

1982

5.9

2007

8.1

2012

5.8

1982

5.2

2008

6.3

1965

6.7