1991

7.4

2003

6.0

1995

6.5

1978

6.1

2013

1.7

2004

5.2

2006

6.7

2005

6.3

2013

6.2

2014

4.8

1970

3.8

1997

7.6

1967

6.9

2014

6.0

2006

4.5

1969

4.6

1981

4.6

2010

5.6

2021

3.6

1999

4.7