1977

7.7

2001

5.5

1974

7.2

1999

5.8

2007

5.0

2008

2.0

1997

7.0

2006

7.4

2006

6.2

2001

7.8

2018

6.1

2002

5.2

1959

7.7

2005

6.7

2018

5.0

2010

5.1

1970

7.2

1995

6.4

2007

6.8

2009

0.0