I define "active" in accordance with the FAA's definition: "An active aircraft is one that flies at least one hour during the year."
The Bureau of Transportation Statistics (BTS) provides a summary of aircraft registered based on aircraft configuration (fixed wing, rotorcraft, single/multi engine, turbo-prop, jet, etc.) and GAMA has a report on the annual shipments, but not the totals of active aircraft.
The FAA's downloadable aircraft registration database is cryptic to the point where I can't figure out what a specific entry means, and the online search interface returns data for one search at a time.
Is there a data source that provides the count of a given make and model across the active fleet of aircraft in the US?
(PS: If there is some trick to decrypting the FAA registration database that would be be great to know as well!)