New answers tagged tags
The API is not a good tool for this (more below). Use the Stack Exchange Data Explorer (SEDE) for this kind of bulk analysis. For example, this SEDE query shows the number of unique users who asked and/or answered in the PHP tag: Unique, Overall, Active Users: 384,835 Active Question Askers: 256,140 Active Answerers: 209,108 ...
Top 50 recent answers are included