1995

7.8

2012

7.3

2006

8.6

1987

8.4

2005

7.0

1985

7.4

2011

8.3

1999

8.6

2020

8.4

2015

7.5

1993

7.9

2004

8.2

1983

8.1

2005

8.7

1994

8.4

2018

7.4

2018

7.4

2014

8.5

2002

8.6

1966

7.3