1953

7.2

2014

6.3

1988

6.5

1989

5.5

2006

6.7

2013

6.5

1999

5.9

1965

6.4

1971

7.4

2005

6.3

1990

6.5

2011

6.6

1966

6.2

2001

6.8

2000

6.4

2008

6.8

2017

6.9

1990

7.4

1993

6.5