Piper Jaffray analyst Gene Munster says in a note to clients — as reported by “AppleInsider” (http://www.appleinsider.com) — that the latest U.S. sales data from the NPD Group (http://www.npdgroup.com) suggests Apple sold around 4.9 million Macs last quarter, a number “that will likely be seen as a mild disappointment on Wall Street.”

That’s down 300,000 units from Munster’s previous prediction. Domestic NPD retail data for all three months of the December quarter shows U.S. Mac sales up 12% year-over-year. Munster’s latest projection calls for Apple to see growth of 18% year-over-year. At 6% higher than NPD’s data, the projection matches the differential of the September quarter, when actual growth was 26% and NPD’s domestic data saw a 20% increase.

And, as “AppleInsider” notes, the latest data suggests Apple is on pace to match its previous best for Mac sales in a three-month span. The company’s current record came in the September quarter when it achieved sales of 4.89 million Macs.,