DF = data.frame(
    company=c( rep( 'Cutter', 6 ), rep( 'Abbott', 6 ), rep( 'McGaw', 6 ) ),
    number=c( 255, 264, 342, 331, 234, 217, 105, 288, 98, 275, 221, 240, 577, 515, 214, 413, 401, 260 )
)