1990

6.9

2007

8.5

2001

7.6

2006

8.6

1973

6.8

1994

8.4

2013

7.5

2004

8.0

1964

7.4

1987

8.4

2016

7.1

2009

7.1

2017

7.5

1999

8.7

2006

7.4

1987

7.6

2004

6.6

2000

8.0

1999

7.9

2016

7.7