1993

5.5

2015

8.4

2003

5.8

1990

4.7

2008

7.3

2011

6.4

2014

4.5

2002

6.3

2012

6.9

1986

7.1

2013

6.7

1968

6.4

1984

6.5

2012

4.5

2016

6.7

2014

6.0

1973

7.5

2014

8.4

1989

6.2

2014

8.5