to

The month filter is scoped on Created_Time. Filtering to a month shows the cohort of leads created that month and how far they have since progressed — this is not the same as demos that happened that month.

Lead funnel

Each lead's stage is the deeper of two independent readingsCurrent_Status and Demo_Status — whichever field shows more progress wins. A drop at any point splits into leads that explicitly said no (lost) and leads nobody said no to, who just went quiet (stalled). Stalled is the working list.