1991

0.0

1999

4.5

2007

5.6

2002

6.8

2001

5.1

1987

6.9

1983

5.4

1989

4.5

1985

5.8

1994

4.1

1976

2.0

1969

3.0

2009

6.6

2006

6.6

1997

5.9

1990

6.8

2006

6.3

2016

5.4

2016

4.0

1999

6.4