1983

7.2

1971

8.2

1994

8.7

2000

7.1

1972

8.7

1996

7.9

2008

8.5

2009

7.3

1975

8.4

1999

8.4

1982

8.1

2011

7.1

2016

6.0

1985

8.3

2001

7.8

2016

7.6

2019

8.5

2007

7.2

1994

8.5

2016

7.9