CREATE TABLE table_38311 ("Start month" TEXT, "End month" TEXT, "Cover" TEXT, "Spine" TEXT, "Indicia" TEXT, "Masthead" TEXT, "Number of issues" FLOAT)

How many issues end on jan 72?
SELECT SUM("Number of issues") FROM table_38311 WHERE "End month" = 'jan–72'
SELECT SUM("Number of issues") FROM "table_38311" WHERE "End month" = 'jan–72'