1972

7.7

2006

7.3

1977

7.1

2001

6.0

1960

6.9

2005

6.7

1997

7.3

2007

5.7

2002

7.4

1997

7.4

2014

5.1

2006

6.2

2007

6.5

2004

5.6

1993

4.5

2002

6.0

1987

6.2

1971

7.2

2003

6.0

1989

6.1