1956

7.6

1998

6.5

1997

6.1

1959

7.1

2006

6.0

1959

6.3

1988

4.0

1976

5.9

1999

6.5

2001

6.6

2003

6.1

2014

5.5

1982

7.2

2003

6.3

2000

7.4

2001

5.9

2002

6.2

2004

6.2

2017

7.0

1990

6.5