1983

5.9

1999

5.3

1989

5.8

1964

6.6

2014

5.0

1982

4.8

1993

6.2

2009

6.1

1991

8.3

1996

7.9

1991

8.1

1995

7.0

2006

7.4

1984

6.2

1987

6.5

1996

6.0

2016

4.8

2000

6.3

1991

6.3

2001

6.2