1970

5.6

2008

6.8

2003

7.2

1999

6.6

2001

4.8

2007

7.2

1998

7.5

1992

6.6

1983

7.4

1995

7.3

1982

7.2

2003

5.9

1995

7.3

2002

6.6

2016

6.1

1991

2.0

1988

5.0

1997

6.3

1984

6.8

1994

6.7