1996

6.4

1970

7.2

2001

7.3

1982

5.7

1964

7.1

2005

6.3

2005

4.0

2005

5.3

2002

6.8

1979

7.2

1984

6.5

2003

5.9

1980

6.0

1981

6.8

2013

8.5

1988

6.3

1992

7.4

2016

3.3

2007

6.5

2008

8.5