1990

6.8

2019

6.0

1987

6.3

1968

6.2

2008

6.4

1999

5.9

2009

6.6

2000

6.7

1995

6.5

1991

7.3

1952

6.7

1996

7.0

2002

7.1

2016

4.5

2002

7.4

1998

6.5

2007

6.4

1958

6.0

2017

6.5

2020

7.5