1990

7.5

2002

6.0

2007

5.6

1996

6.7

2010

5.2

1992

6.7

1978

6.1

2013

7.6

2011

7.1

2012

5.5

2002

6.7

1998

8.6

2009

7.0

1999

7.8

1949

6.9

2008

8.0

1988

7.5

2005

6.3

2013

7.4

1939

7.6