1960

6.9

2001

7.3

2004

6.9

1975

6.9

2006

5.4

1958

6.4

2005

5.6

1997

6.1

1964

6.7

1959

7.1

1999

6.1

1963

7.7

2007

4.8

2014

6.5

1992

1.7

1995

7.4

2007

7.2

2007

5.9

2002

6.4

2000

6.1