===Data by zip code===
1. *Population data - US Census Bureau
https://www2.census.gov/programs-surveys/popest/datasets/
2. *Income data - The Internal Revenue Service
https://www.irs.gov/uac/about-irs
3. *DCI index, to assess the economic well-being of communities
http://eig.org/dci/interactive-maps/u-s-zip-codes