After 5 years of daily use it is 84%. Is that good or bad? Read online the Apple Store diagnostic tools measures iPad battery health differently by padding it as much as 10% more. So if you try my method you qualify for a paid battery replacement via refurb with fresh new battery by having your iPad self report itself as 70%.
This link provides instructions on how to extract it from Settings > Privacy & Security > Analytics & Improvements
This link provides instructions on how to extract it from Settings > Privacy & Security > Analytics & Improvements