There were initially three schedules: A, the Cash Account, B, the Stock Account, and C, an explanatory sheet giving further details. Schedule D, the Colportage Account, was introduced later, and E, the Property Account was added in the twentieth century. The returns are either quarterly, half-yearly, or occasionally yearly. From 1939 there are four-monthly and annual returns. From 1961-1966 the forms were weeded drastically, leaving only a Balance Sheet and a Statement of Income and Expenditure. The acconts form 1961-2 are missing entirely for some countries. Although many countries had their own separate Agency, others formed part of a large Agency comprised of several countries. As the boundaries of the Agencies changed over time, some countries were part of more than one Agency during the period covered by the schedules. The arrangement of the schedules reflects the division of the countries into either individual country Agencies or into Agencies containing several countries.