1990

6.3

2002

7.2

2004

7.4

2006

6.4

2005

6.6

2000

5.0

2007

6.8

2007

6.7

2000

6.0

2018

7.0

1997

7.5

1999

6.7

1978

6.3

2017

6.0

2018

4.4

1940

6.5

2021

6.1

2016

2.5

2007

9.0

2008

9.0