A number of memory spaces are defined for a memory structure. Transaction data is received, and financial transactions are scored based on the transaction data to generate a batch of scores for the financial transactions. A score range is divided into k bins, each of the k bins representing one memory space of the memory spaces of the memory structure. The batch of scores are aggregated by storing a count of each score in a memory space, and a percentile is computed for each score in the batch of scores based on a set of values associated with each score. Each new financial transaction is scored to generate a new score, and a new percentile is assigned to the new score according to the set of values. The new percentile is then translated to a calibration score with fixed percentile characteristics according to a fixed reference curve.