1999

8.2

1997

7.7

2014

5.5

1971

6.4

2007

6.6

1995

7.3

2016

7.4

2002

5.3

1999

6.7

1999

6.8

2017

7.4

1967

6.7

2013

4.5

2017

6.9

1998

7.1

1993

6.0

2003

6.8

1982

5.2

2001

6.3

1988

6.6