1997

7.4

1996

7.9

1995

7.0

2003

7.8

1991

5.0

2002

6.4

2009

8.0

1976

4.9

2001

9.0

2019

6.0

2006

6.2

1981

6.5

1979

7.2

1995

6.3

1998

6.8

1993

5.9

2019

0.0

1978

7.2

1985

0.0

1989

0.0