Avast Data Shredder

Hello, in the last few days I have shredded previously deleted files using Guttman’s algorithm. It took a few days, today, when I looked at what percentage is already shredded, there was 59%. After a while when I was leaving the computer, I noticed that everything was shredded. Please don’t know if the percentages were just wrong or should I do it again? Thank you in advance for your answers. I would also like to add that I moved some files from drive C to drive D. (I shred deleted files on drive D.)

If all items were shredded your fine

Hello, please can you tell me how can I know if All my deleted files was shredded?