From Thursday-Sunday kid laundry:
On the other hand, I have divised a clever index which can be used to track potty training progress scientifically. It is a simple ratio of the number of shirts in a load of laundry to the number of pants. When a child is fully potty trained the index would be 1.0. When your child is just beginning to learn the index would be much lower, maybe 0.25. When you have been wearing undies since May and you just wake up one day and decide you don't want to use the potty anymore the index (our current index) is more like 2.5*10-16.
Banging my head against the wall over here.