1981

5.2

1997

5.4

2016

5.5

2001

1.0

2006

6.0

2001

3.7

1994

0.0

1990

0.0

1986

5.3

1996

6.5

2001

9.4

2004

6.1

1995

4.8

1976

5.7

1999

6.8

1995

4.6