Here is a great link describing the poverty levels since 1959.
http://www.census.gov/hhes/poverty/histpov/hstpov1.html
you can see the figures for families of all numbers in the table... but here is an interesting fact. for a couple living 1983, the poverty line was at $7,938. this same measure has been bumped up to $14,680 in the year 2003.
that's nearly TWICE what it was just 20 years ago. surely this must outpace inflation (does it?) and the CPI. medicare, welfare and unemployment benefits have risen since then... is it not possible that the standard for poverty has improved since 1983?