2001

7.3

1997

6.8

2005

6.7

2005

6.8

2017

4.9

2006

5.4

2001

6.1

1976

3.3

1964

6.7

1959

7.1

2004

6.5

1992

5.7

1980

3.1

2007

7.2

2009

5.9

2007

5.9

2006

4.9

1986

6.3

2002

6.4

1978

6.5