1989

5.2

2013

6.1

1980

6.7

2018

7.6

1990

7.5

1972

6.4

2020

6.7

2000

5.2

1998

7.3

2012

5.6

2011

5.9

2003

7.4

1989

8.3

1994

4.6

2009

6.0

2002

7.1

2008

5.4

2007

6.5

1960

6.5

2014

6.1