1953

7.2

2015

7.4

1991

6.2

2014

7.0

1996

7.8

1988

6.5

2010

7.1

1980

5.9

2009

7.7

2019

6.5

1975

6.4

2000

5.1

2019

6.5

2006

6.4

7.8

2002

6.5

2011

6.6

2004

6.4

1993

6.1

2012

5.7