2004

6.3

1999

7.1

1992

7.4

2012

6.0

1995

6.4

2004

4.8

2008

5.6

2001

6.4

1986

4.6

1997

6.6

2008

6.6

2004

1.0

1982

6.2

1975

5.8

1970

4.8

1979

4.2

1969

5.5

1968

5.4

1982

6.1

2012

4.0