1967

7.6

1988

6.3

2008

6.1

1986

6.7

1979

6.6

2004

5.3

1985

7.5

1984

6.4

2002

6.6

2002

6.2

2008

4.5

2006

6.8

1993

6.8

2002

5.9

2003

6.8

2016

4.4

1993

6.7

1988

7.6

1976

7.8

2006

5.5