1991

6.8

2020

5.3

2001

7.7

2004

7.3

2011

6.6

2005

7.1

1990

7.7

2019

5.6

2017

7.3

1984

7.0

2013

5.2

2006

7.8

1984

6.3

2018

6.1

2017

6.8

2006

6.7

1959

6.9

2000

6.4

1934

6.4

2007

6.7