to answer your question without really answering it.......

When I first started with my airline it was mostly 4 day trips. Then it became nothing but 2 weeks of 1 day trips a month followerd by 2 weeks of highspeeds/cdo's. That lasted about a year or so. Then it was 2-2 day trips back to back. Then it was mostly 4 day trips. Then back to 2 -2 day trips. Now we are back to mostly 4 day trips with a handful of 3 days and a sprinkling of 2 day trips and CDO's......that is for my base at least.

so there really is no set answer...