Use an open ended reference.
A range reference has two parts, the address of the start cell and the address of the end cell. On the A1 notation usually the cell address includes a letter to specify the column and number to specify the row.
- A:A specifies the whole column
- A2:A specifies that the start cell is A2 and that the last cell is the last one of the A column.
For the specific case in the question, instead of