If I'm not mistaken, the "Usage" column for private orbs is not valuable in the UI. Since "private" orbs are private to the org, can't be shared to other orgs, and the usage column only indicates the usage in orgs, all private orbs would always show 1? It might make more sense to suggest "N/A", with a tool tip to this affect. Even better, would be data about how many projects in an org are USING a private orb.