2005

6.7

2008

6.3

2006

6.2

2007

6.4

1970

6.7

1991

6.3

1992

6.1

1992

5.7

1985

6.5

2005

6.3

2003

5.2

1962

6.7

1984

6.9

1986

6.6

1992

5.8

1971

6.7

1989

6.8

1993

5.3

2007

5.5

2002

5.4