1978

6.0

1971

7.5

2006

5.8

1971

5.1

1991

9.0

2002

5.7

1999

1.0

2014

6.6

2002

6.5

1951

6.3

2011

6.2

1997

6.2

1991

7.4

2005

6.7

1974

7.5

2002

2.1

1998

6.3

2008

3.3

2003

4.7

2008

2.9