1986

7.0

2005

5.9

1995

6.8

1990

6.7

2009

6.3

1994

6.2

2006

7.8

2003

6.3

2001

6.3

2013

6.6

1982

5.2

2000

6.6

2002

7.4

1956

7.1

1995

6.9

2010

5.9

1989

6.3

1968

6.9

1999

7.6

2016

6.7