I haven't run some massive analytical dataset but this is a pretty reliable range for a typical ticket. There are outliers based on market competition or when you are on the very boundaries of basic economy availability (e.g., V availability may be >30%, H may be <20%.. if H has E fares available, I always forget the exact cutoff). When there is nonstop competition (e.g., to major competitor hubs) and in goldilocks time zone for pricing, it will often by >30%. But in general 20-30% is a good rule for a 'typical' route.

Just go test out some bookings and you'll see most fall in that range.

This is a bit offtopic so I won't continue on this further.. feel free to DM me or take it to the Basic Economy thread!