2007

8.1

2015

6.7

1990

6.0

2009

6.1

1987

6.3

1968

6.9

1987

5.5

2008

8.0

2014

5.3

1989

6.3

2016

6.7

2008

7.1

2015

6.0

2002

5.7

2000

9.4

1987

4.0

1931

5.8

2013

6.3

2010

6.5

1996

5.8