1999

7.0

2004

7.1

2008

7.5

1987

6.9

2015

8.1

2008

5.3

2000

7.3

1986

6.9

1980

6.4

1963

7.5

2014

4.6

2012

6.2

2014

5.0

1991

5.5

1980

5.8

2017

6.7

1964

5.5

1986

6.4

2016

6.5

1988

6.3