1960

8.4

2006

6.6

1999

6.5

1999

6.8

2004

6.0

2007

6.3

1953

6.9

1998

6.6

2013

5.1

2003

5.9

1958

7.8

2000

6.3

1968

7.2

1987

7.3

2000

6.4

1991

7.5

2000

5.9

1993

7.5

2002

7.0

2006

5.4