1993

6.0

1988

5.6

2005

6.7

1980

7.3

1999

7.1

1987

6.9

1982

6.1

2008

4.1

2000

4.3

1978

5.0

1966

6.5

1967

6.6

1965

6.3

1964

6.6

2000

4.7

2000

6.4

2001

5.8

2003

6.0

2006

5.5

2013

4.8