1998

6.8

1997

5.8

1998

5.0

1999

5.7

1998

6.5

1999

6.8

2001

6.7

1995

7.3

1934

6.1

2013

7.2

1988

7.6

1976

7.8

1996

6.9

2007

6.5

2007

5.7

1985

7.5

2002

6.4

2004

6.7

2003

6.6

2015

0.0