Now let us turn to columns in Table 1 . Columns ( 1 ) , ( 3 ) , ( 6 ) , and ( 9 ) , labeled Volume show , in millions , the total First-Class Mail pieces broken-down by sector for FYs 1987 , 1990 , 1993 and 1997 , respectively .
Columns 1,3,6 , and 9 show first-class mail by sectors for years 1987-1997 .