1997

7.4

1964

7.2

1975

7.4

2004

7.8

1961

7.7

1993

5.1

2006

8.3

2007

7.7

1985

7.7

2005

0.0

2002

7.4

1981

7.1

2009

7.5

2015

7.8

1960

0.0

2015

7.1

2001

6.1

2008

6.4

1990

7.6

2015

7.5