At last check, all 917 core-based statistical areas (CBSA) have been scored. A CBSA is an urbanized cluster of at least 10,000 people. The data for “Active Builders” and “Active Subdivisions” is more limited, however, and exists for only 381 metropolitan statistical areas (MSA). An MSA is an area with at least 50,000 people. In short, the data covers over 90% of where American households reside.