1963

6.9

1999

5.1

1990

6.1

2018

6.7

2008

7.5

2009

5.0

2010

7.4

1966

6.3

1996

6.1

1988

6.5

1985

4.3

2005

6.4

2006

6.1

1996

5.8

2005

6.9

2015

6.9

2012

5.6

1994

6.6

1979

6.3

1971

7.4