1989

7.1

2007

5.9

2001

7.8

1985

8.3

1994

8.7

2009

7.6

1997

7.9

1990

7.4

2015

7.9

1972

8.7

2010

8.4

2008

8.5

2006

7.5

1979

8.2

2016

7.6

2019

8.1

2013

8.1

1995

8.0

2018

7.4

2007

7.1