1993

5.1

1991

5.3

2011

6.8

1997

7.2

1992

1.5

1971

8.1

2005

6.2

2007

5.6

2000

3.0

2009

7.0

2000

7.9

2009

6.0

2017

7.4

2003

6.0

1986

0.0

2011

4.8

1983

6.3

2003

6.6

0.0

1996

8.7

2004

6.7

2007

7.6