1977

6.3

1994

6.2

2000

5.1

2017

6.9

2014

5.7

1980

6.4

2016

6.7

2000

6.4

2006

6.1

2011

6.2

1996

5.8

1953

5.9

2019

6.5

2010

5.2

2009

7.9

2015

8.0

2017

6.6

2005

5.2

1990

5.5

2016

7.3