1968

7.6

2007

4.2

2003

7.8

2013

6.7

1975

5.6

2006

7.4

1976

5.6

1988

7.1

1969

3.5

2001

5.1

1964

4.4

2013

5.8

2004

5.5

2009

7.5

1999

5.5

1988

3.6

2004

1.6

1969

6.5

1993

7.7

2002

5.5