Generate a sentence about this data: 1955-1960 CBR* 53.8; Demographics of Niger; 1955-1960 IMR* 171; 1955-1960 NATURAL_CHANGE_PER_YEAR 88 000; 1955-1960 NC* 29.0; PERIOD 1955-1960
Between 1955 and 1960, Niger's crude birth rate of 53.8 and an infant mortality rate of 171 per thousand births resulted in a natural change of 29.0, or 105,000 per year.