function [t,p]=uspop()
% [T,P]=USPOP. US-population data, copied from 
% Harvard Calculus Consortium. 21 data points
% from 1790 to 1990. Population in millions.
%
% According to Lomen/Lovelock's DE text, a rather
% surpringly good fit is based on the observation 
% that (dP/dt)/P is nearly linear in t.
%
% Matthias Kawski. http://math.la.asu.edu/~kawski
%       Old data file. Comments added in Aug 2000.
t=[1790:10:1990];
p=[3.9 5.3 7.2 9.6 12.9 17.1 23.1 31.4 ...
   38.6 50.2 62.9 76.0 92 105.7 122.8  ...
   131.7 150.7 179 205 226.5 248.7];