Upper Class:
$170,000+ a year
5% of the nation fits in here.
Middle Class:
$170,000-$25,000 a year
45% of the nation fits in here.
(The break down:
Upper-middle:
$80,001-$170,000 a year
Average-middle:
$40,001-$80,000
Lower-middle (working class):
$25,000-$40,000 a year)
So that is 50% of the nation, are in the Upper Class, or Middle Class. The other 50% makes up the Lower Class (20%, 25K-15K), Working Poor (12%,15K-10K), and other 18% make less than 10K a year.
(Came from a Society book I had, info was printed in 2003)