%USPOP: Defines decades and corresponding U.S. populations.  Year 0 corresponds with 
%the first census in 1790, and year 230 corresponds with the last census
%in 2020.
decades=0:10:230;
pops=[3.93 5.31 7.24 9.64 12.87 17.07 23.19 31.44 39.82 50.16 62.95 75.99...
        91.97 105.71 122.78 131.67 151.33 179.32 203.21 226.5 249.63 281.42 308.75 331.45];