1977

7.7

1989

7.1

2018

7.2

1990

6.4

2014

7.4

2008

5.3

8.0

2006

6.8

2000

7.6

1996

5.9

1981

6.8

1998

6.7

1995

7.4

1996

6.1

1995

6.3

2016

7.0

1970

0.0

2021

6.3

2001

5.1

1988

6.7