1998

6.1

1996

6.5

1973

6.8

1982

8.0

2006

4.1

2011

6.6

2018

5.9

2003

5.0

1961

7.7

1988

5.5

1959

6.0

1966

6.2

1999

6.7

2015

6.3

1972

6.2

1995

4.6

2009

7.4

1955

6.9

2009

7.3

2016

7.4