The number of studies with available phylogenetic data---as tree files, alignments files or both procured either from online archives or by direct request---organized by year of publication (barplot).
Grouped here are the data referred to in the study: Data sharing in public health emergencies - A study of current policies, practices and infrastructure supporting the sharing of data to prevent and
"The majority of US phase 3 trials were retrospectively registered. Only three out of ten studies that were completed before January 2011 have results available, data was submitted to ClinicalTrials.g
