First I projected all New York census tracts into NYC taxi zones since taxi zones were much larger than most tracts. With all the intersection results, I could tell which taxi zones each census tract were divided into and their corresponding proportional areas. It is assumed that inside each taxi zone the possibility of FHV pickup is the same, so we could calculate the each tract's pickups from the intersections with different zones by adding all proportional amount togethers.  Then I combined all 12 monthes' FHV trip datasets together, then .