Labels:screenshot | line | text | plot | diagram | font OCR: 1840 Source: Statistical Abstract of the United States, U. S. Department of Commerce 1850 1860 1870 1880 1890 1900 1910 1920 1930 1940 1950 1960 1970 1980 1985 1986 1987 1988 1989 1990 1991
