1993

4.9

1991

4.5

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

5.9

2017

7.4

2003

6.0

1986

0.0

2011

4.8

1983

6.4

2003

6.6

1996

8.7

2004

6.7

2007

7.6