1956

6.6

2011

8.3

1998

7.8

1999

7.6

1992

8.1

1999

8.0

1990

8.5

1995

8.4

2014

6.5

2003

8.0

2001

7.9

2009

8.2

2000

7.4

2015

7.8

2001

7.9

1994

8.3

1972

8.7

2011

8.1

2015

7.6

2016

7.9