rownames,time,value
1,1790,3.93
2,1800,5.31
3,1810,7.24
4,1820,9.64
5,1830,12.9
6,1840,17.1
7,1850,23.2
8,1860,31.4
9,1870,39.8
10,1880,50.2
11,1890,62.9
12,1900,76
13,1910,92
14,1920,105.7
15,1930,122.8
16,1940,131.7
17,1950,151.3
18,1960,179.3
19,1970,203.2