1995

5.1

1987

5.6

2000

6.6

2002

4.0

2006

6.8

1988

7.2

1996

5.7

2000

5.0

2001

6.8

2001

3.3

2000

6.5

1997

0.0

1962

6.9

2006

6.2

2003

7.2

1990

7.3

1998

6.0

2013

5.0

2016

6.0

2017

6.1