1800 5.3
1810 7.24
1820 9.64  
1830 12.68
1840 17.06
1850 23.19
1860 31.44
1870 38.56
1880 50.19
1890 62.98
1900 76.21
1910 92.23
1920 106.02
1930 123.20
1940 132.16
1950 151.33
1960 179.32
1970 203.30
1980 226.54
1990 248.71