2002

4.8

2006

4.6

1995

6.2

1984

6.4

1993

6.8

1985

7.1

1996

7.2

2002

6.7

2008

6.0

2002

6.2

1991

8.3

1946

7.7

1955

7.3

2004

7.3

1969

7.4

1995

7.2

2001

6.1

1992

5.8

2014

5.5

1999

5.4