A copy of the records on contracts.ocp.dc.gov, the website where DC's Office of Contracting and Procurement publishes contracts, purchase orders and payments, as we pulled them. About this source. Not a complete record of District contracting or spending.
One row per contract option period: a contract with a base period and two option years is three rows. Amounts are shown and totalled for base periods only: what the first period authorises the District to spend, not what was paid. Option-period amounts are left out because about three in ten we checked disagreed with the District's own paperwork (how we know). Every other field below is the District's, as published: agency, vendor, contract type, market type and commodity code are what was entered on DC's site, not categories added here.
Group the filtered rows by one or two fields. Every value is as the District entered it.