1988

5.5

1983

7.3

1967

6.6

2011

6.9

1980

8.4

1995

7.3

1999

5.9

2015

6.2

2005

6.8

2011

6.7

1981

5.8

2009

6.6

2007

4.8

1977

8.2

2007

6.9

2011

7.5

2012

7.3

2009

7.1

1985

6.2

1972

8.7