I’m going to guesstimate 100K pages a day, based on 5 day/wk and 50wk/yr.
Can we assume that he got soft copies and not all hard copies?
Then it would depend on the format of the files that he got. DOC, PDF, TXT etc.
What is the file size or volume?
You can get over 250 gig memory the size of your pinky nail.