1987

7.8

2008

7.6

2020

8.3

2002

7.5

2011

6.7

1979

6.8

2004

8.0

2017

7.9

2012

6.6

1999

7.0

2017

7.4

1990

7.9

2016

8.6

2002

7.1

1999

7.5

2019

8.4

2000

6.9

2007

7.4

2015

6.5

2018

7.3