1993

7.0

1999

7.2

1976

7.8

1979

7.3

1982

6.9

1985

7.1

1990

5.8

2014

3.3

2007

6.7

1976

7.8

2007

5.2

2005

6.4

2004

6.9

2007

6.3

2006

6.8

1992

6.6

1995

7.4

2001

5.1

1996

6.1

2008

6.5