The number of columns depends on the number of data in you list. The 5th column exist , it is just empty because in your dataset does not produce enough points to fill the column. Look at this
Table[Multicolumn[{1, 2, 3, 4, 5}, n], {n, 1, 5, 1}]
Table[Multicolumn[{1, 2, 3, 4, 5, 6}, n], {n, 1, 5, 1}]
Table[Multicolumn[{1, 2, 3, 4, 5, 6, 7}, n], {n, 1, 5, 1}]
Table[Multicolumn[{1, 2, 3, 4, 5, 6, 7, 8}, n], {n, 1, 5, 1}]