1978

5.8

1979

4.6

1973

7.0

1971

5.5

2002

4.6

2008

5.3

1991

6.1

1980

7.9

2015

5.6

1994

4.3

1983

7.5

2001

7.0

2004

6.7

1991

6.0

2001

2.3