There are several sources of free education data on the web. Both UNESCO and the World Bank have extensive collections of data available in easily downloadable format. Both sets of data include numerous tables, which have a large variety of data at a national level with time series.
UNESCO -- the main UNESCO site provides a list of reports which can be downloaded as .pdf files, these are available at http://www.uis.unesco.org/Pages/default.aspx. Data in downloadable spreadsheet format is available at http://data.uis.unesco.org Use "Popular Queries". World Bank -- The World Bank data uses much material from UNESCO and incorporates it with data from other sources. The World Bank provides time series data in the World Development Indicators and a dedicated education database both available at http://databank.worldbank.org/data/databases.asp Use either the WDI database or search for Education.UNICEF-- The UNICEF page provides a set of "At a Glance" data on population, nutrition, health, education, etc. as it affects children. For individual country data select "Data by Topic and Country", for topic data sets select "Resources. The UNICEF data is available at https://data.unicef.org .
United Nations -- Data on the educational indicators related to the Sustainable Development Goals is available at http:// data.un.org .
Wittgenstein Centre-- Provides education data projections to 2100 generated through query form http://www.wittgensteincentre.org/en/index.htm . Much of this data is available on the World Bank WDI site in a more accessible format.Demographic and Health Surveys (DHS) -- This site https://www.statcompiler.com/en/ provides survey data for education at the national and provincial/state levels. The data is available as spreadsheet downloads and for some indicators, shape files. For all the education variables choose "Complete List" then "Education". For education data select data