1983

7.9

2005

6.3

1981

5.8

1995

7.9

2008

7.8

1993

5.0

1992

6.7

2003

8.3

1980

8.4

1990

6.1

1988

7.5

1991

6.2

1997

7.6

2019

7.2

1982

6.1

2011

5.7

2019

6.8

1987

6.5

2015

7.4