1991

7.0

2012

7.8

2010

7.4

1981

6.2

2014

5.8

2020

6.7

2008

6.5

2017

6.1

2010

7.4

1992

6.4

1984

7.2

1968

6.9

2020

6.5

2015

6.3

1999

5.9

1962

6.9

1998

6.0

1988

6.5

1993

6.5

2003

6.7