You can compare diagnostic reference levels (DRLs) from different years for the same exam; these correspond to the 75th percentile patient dose for a particular

You can compare diagnostic reference levels (DRLs) from different years for the same exam; these correspond to the 75th percentile patient dose for a particular imaging study. It can be a little annoying to find older DRLs (I just tried). NCRP 172 (published 2015) provides a direct comparison of digital to film for some examinations. For upper GI fluoroscopy without oral contrast the DRL for film is 3.9 mSv and for digital is 1.5 mSv. I think this is roughly typical.