"time"	"uspop"
1790	3.93
1800	5.31
1810	7.24
1820	9.64
1830	12.9
1840	17.1
1850	23.2
1860	31.4
1870	39.8
1880	50.2
1890	62.9
1900	76
1910	92
1920	105.7
1930	122.8
1940	131.7
1950	151.3
1960	179.3
1970	203.2