《礼记·王制》
百亩之田按其土质肥沃分为三等，上农夫每一百亩田养活九人，稍次一些的养活八人；中农夫每一百亩田养活七人，稍次一些的养活六人；下农夫每一百亩养活五人。
百亩之分：上农夫食九人，其次食八人，其次食七人，其次食六人；下农夫食五人。
A hundred acres of fields were divided into three classes according to the fertility of their soil; a higher-level farmer could support 9 persons with every 100 acres of field, while a slightly lower-level farmer could support 8 persons; a middle-level farmer could support 7 persons with every 100 acres of field, while a slightly lower-level farmer could support 6 persons; a lower-level farmer could support 5 persons with every 100 acres of field.