This repository contains the data used in the blog "Citations to Astronomy Journals 1: The growth of interdisciplinarity", Michael J. Kurtz and Edwin Henneken. Each file has a header with a description of the data contained in the file. Table 1 consists of the bibstems for the journals in the main sample. Table 2 contains the individual data for each journal in the format journal, indicator, value, year. Table 3 has these data for all refereed journals (including the journals in the main sample, and all the rest). All three data files are ASCII files with space-separated columns. The term "bibstem" is the journal abbreviation used within the Astrophysics Data System. The complete list of bibstems is provided here: http://adsabs.harvard.edu/abs_doc/journals2.html. The bibstem is used in the ADS bibliographic identifier ("bibcode") with the convention that ampersands are replaced by plus signs (see: http://adsabs.github.io/help/actions/bibcode).