*4.5. Data Availability*

The code that we make available as part of this work allows to download and process all available Project Gutenberg books, facilitating the task of keeping an up-to-date and homogeneously processed dataset of a continuously growing resource. In fact, new books are added to Project Gutenberg daily. An unwanted consequence of this feature, however, is that two local versions of the SPGC might differ if they were last updated on different dates. To facilitate and promote reproducibility of our results and possible subsequent analysis, we provide a 'frozen' copy of the SPGC, last updated on 18 July, 2018, containing 55,905 PG books. All statistics and figures reported on this manuscript are based on this version of the data. This data is available at https://doi.org/10.5281/zenodo.2422560.
