Abstract: A system is disclosed for determining and recording a plurality of individual rates of occurrence of predetermined events over a time span wherein the system utilizes a sensor-accumulator which senses the occurrence of a plurality of events over a predetermined time and translates the accumulated total into a binary expression. The binary expressions are periodically written into a dynamic recirculated memory in a serial fashion and after a predetermined time are all read out to a printing device. The position of the last entered binary expression in the recirculating memory is indexed by means of a counter which is reset to zero upon entry of a word and initiates counting upon the entry of the last bit of the word. A decoder is set to generate a signal each time the counter reaches a count equal to the memory capacity to thus index each complete recirculation of the memory past the point of the last bit entered.