1999

7.1

2010

5.5

2017

6.1

2004

4.8

1976

6.7

1934

6.4

2007

7.7

1984

6.3

2015

5.1

1983

5.7

2001

6.2

2016

6.2

2018

7.0

1991

7.7

2008

5.7

2011

4.7

1984

6.3

2010

7.0

1993

7.2

2003

5.0