Had to check and apparently as early as 1880 the literacy rate in Finland was 98%. Although the majority of the population, 85% could only read and not write!

Here in 1890: 78% couldn't read or write, but some people suggested by then that an illiterate person should not be allowed to marry, and should enjoy the same level of protection as a pet (reading from a paper). Apparently, that was not a good enough carrot.