1968

7.6

1985

6.0

1975

5.6

1976

5.6

1988

7.1

2001

5.1

2015

3.0

2007

4.2

1999

4.2

2017

6.7

2006

7.4

1997

1.8

2003

7.8

1988

3.0

1993

2.0

1995

2.0

2009

7.5

2002

6.4

2016

0.0

1993

7.7