My Monday morning MCO - MDW - OMA and return Thursday afternoon have been over 80% full on WN. The seat gods have been good to me though I have had an empty middle seat about 50% of the time. The OMA - MDW and MDW - OMA legs are almost always completely full. I did notice a lull in late September and early October (to/from MCO) presumably because parents didn't want to take the kids out of school at the beginning of the school year.