1991

7.9

1998

8.5

2005

8.7

2002

7.9

2006

8.6

2003

7.9

2008

7.6

2020

8.2

1982

7.6

1983

7.3

2009

6.8

2011

8.5

2018

8.3

1988

8.1

2010

7.7

2017

7.5

1995

7.6

2021

8.8

1968

7.3

2020

7.2