1962

7.9

2004

8.0

1995

7.6

2001

7.8

1997

6.6

1999

6.3

2002

6.0

1993

5.5

1989

7.8

1986

7.2

1990

7.5

1996

7.3

1984

7.7

1991

8.1

2003

6.2

1989

6.9

1991

6.3

2007

6.1

1971

6.4

2008

6.6