1999

0.0

2015

5.8

2002

7.1

1997

6.9

1987

8.1

1989

7.4

2007

7.9

1998

7.2

1970

7.5

2008

6.2

2005

6.6

1972

4.0

2007

6.6

2013

6.0

2016

7.3

2009

4.2

2013

6.7

2003

7.1

1978

6.2

1936

5.7