I just discovered this but Baseball Cube has a page where you can look up year by year what the prospect rankings were for a particular team based on the ranking service. Years available include:
- Top 10 Astros Prospects per Baseball America (1983-2000)
- Top 30 Astros Prospects per Baseball America (2001-2021)
- Top 30 Astros Prospects per MLB Pipeline (2016-2021)