1999

6.6

1998

6.1

1993

7.3

1978

6.3

1994

7.3

1995

6.2

1984

6.8

2004

6.6

2006

6.5

1970

7.5

1988

6.8

2007

5.6

2005

6.9

2004

7.1

1989

6.2

2006

7.6

1982

5.2

1996

6.4

2019

7.7

1978

8.0