Image formation apparatus and image formation part selection method

An image formation apparatus comprising:

• a plurality of image formation parts each of which includes:
• a developer image development part configured to form a developer image;
• a developer container that accommodates a developer to be supplied to the developer image development part;
• and a deteriorated developer container that accommodates a deteriorated developer discharged from the developer image development part;
• a collection part that collects a value based on a history of printing rates of each of the plurality of image formation parts;
• a printing rate calculator that calculates a printing rate of a received print data;
• and
• an image formation part selector that selects, based on the value based on the history of printing rates of each of the plurality of image formation parts collected by the collection part and the printing rate of the received printed data calculated by the printing rate calculator, one of the plurality of image formation parts, to be used for performing printing of the received print data.