Stamp No.     Issue date     Number issuedD90.1 10.10.1966   2,000,00012.11.1967   4,000,000 6. 6.1972        5,000,000D90.2 10.12.1966   4,700,00012.11.1967        3,000,00031. 8.1970        6,000,00010. 6.1971        8,000,000 6. 6.1972  10,000,000D90.3 10.12.1966   3,000,00018. 8.1971   1,000,000D90.4 10.12.1966   4,000,00012.11.1967   3,000,00020. 6.1970   9,000,00018. 8.1971   5,000,000 6. 6.1972  15,000,000D90.5 15. 2.1967   3,000,00012.11.1967   3,000,000D90.6 10.12.1966     300,00018. 8.1971   1,000,000D90.7 10.10.1966   3,000,000D90.8 10.10.1966   3,000,00012.11.1967   3,000,00025. 6.1971   5,000,000D90.9 15. 2.1967   4,000,00012.11.1967   4,000,00025. 6.1971   5,000,000　　 　　To meet service needs, a set of 〝Flying Geese in Lines Postage Stamps〞of medium value was issued on several separate occasions. The stamp pictures a flock of wild geese flying in lines as its central design, symbolic of the promptness, accuracy, and orderliness of mail transmission and delivery.　　The paper used for stamps issued before 1971 is yellowish in color and with more fibers, but that used for stamps issued since June 1971 is whiter and with fewer fibers. All stamps issued since June 1970 were gummed. Furthermore, the following stamps then in stock were gummed and put on sale on November 1, 1971：3.50, 1,500,000; 4.50, 2,425,000; 5.50, 4,950,000; 6.50, 2,200,000; 8.00, 5,600,000.