These data and chart present an approximate calculation of the proportion of preprints in biology when compared to publications in PubMed, based on monthly figures and incorporating monthly preprint submissions (or counts) across a selection of servers relevant to biology. Version 1.0 of these data represents data from January 2007 until May 31, 2019 for preprint servers: arXiv q-bio, Nature Precedings, F1000Research*, PeerJ Preprints*, bioRxiv**, Winnower*, preprints.org, Wellcome Open Research*. * Counts may not be specific to biology preprints only; ** Counts may include all versions posted that month, so may be an overestimate for version 1 submissions. From January 2019, data has been gathered manually by the authors, as per the methods described in the .csv here, and is included here in 'Preprints_per_month_direct_2019-01to05.csv'. Until December 2018, monthly preprint submissions data are based on those contributed by Jordan Anaya (ORCID: https://orcid.org/0000-0002-6166-4113) for PrePubMed, source: https://raw.githubusercontent.com/OmnesRes/prepub/master/analyses/preprint_data.txt; Github repository: https://github.com/OmnesRes/prepub; website: http://www.prepubmed.org). Data are not included here, they are provided from the source linked above under MIT license associated with the website code: https://github.com/OmnesRes/prepub/blob/master/LICENSE. A live version of these data and the chart are available from this GSheet: https://docs.google.com/spreadsheets/d/1bkGEcfQcL0LpIanVqNHci1ZFY6oVNGz7IQbEugzkqkU/edit?usp=sharing. Between version updates here, please refer to this sheet for updated counts and method updates e.g. to include more servers and ensure only version 1 submissions are counted. For more information, please contact naomi.penfold@asapbio.org. When presenting these data and/or chart, please attribute to ASAPbio (https://asapbio.org, twitter: @ASAPbio_).