1967

0.0

1978

0.0

1977

6.0

1994

4.9

1996

5.4

2004

5.1

2006

6.4

1987

6.8

1999

7.8

1982

6.1

1974

7.9

1996

6.7

1980

7.3

2015

8.0

2000

4.7

2000

6.4

2001

5.8

2003

6.0

2006

5.5

2013

4.8