2005

6.8

1997

7.5

1975

6.9

2002

6.1

1972

7.5

2007

7.6

2003

6.1

1993

7.0

1993

5.7

2016

5.6

1990

6.4

2006

4.8

1998

6.3

1983

6.5

2000

5.3

1987

6.6

1986

6.7

2006

5.5

1992

4.0

1996

5.6