What do the "spending" categories include in StarCraft II replays?

In a replay, there is a "Spending" display that includes 3 categories:

• Economy
• Technology
• Army

While it seems fairly straightforward that workers = economy, upgrades = tech, army = units, what do unit producing structures count as? Or upgrade structures for Zerg? etc...

Solution 1:

Economy

• Command Centre / Nexus / Hatchery
• Refinery / Assimilator / Extractor
• Supply Depot / Pylon / Overlord
• SCV / Probe / Drone
• Queen

Technology

• Unit producing structures (or in the case of Zerg, buildings which enable the spawning of units from larvae)
• Structures where upgrades can be purchased (e.g. Engineering Bay, Forge, Evolution Chamber)
• Upgrades (e.g. attack upgrades, building armour upgrades)

Army

• All other units

My testing found that morphing buildings (e.g. Orbital Command, Planetary Fortress, Lair, Hive, Greater Spire) isn't counted at all, nor is the process of morphing units (e.g. Overseer). It also seems as if the construction of some buildings (e.g. Infestation Pit) isn't counted either, so it would appear as if the Spending Tab is somewhat buggy.