In 2017, fifteen core system vendors (large and small that provide core to 94% of the U.S. population) sold 232 branded core systems to U.S. banks and credit unions. That was 2.04% of the population. Past history (16 years) the average percent (Mean) of
population was 3%. The Hi was 5.8%, the Lo was 1.6%, the Mode was 2.04%, the Median was 2.06%. Straight from the horses' mouths - requested, calculated, audited, and recorded by me for "Automation in Banking - 2018."