Percentage change

I have a column of figures to which I would like to add the same percentage increase/decrease to each individual line, about 140 lines in total, in the following column! Rather than manually alter each line by the same percentage I believe it is possible to have a formula that would do this by reference to just one cell in which is the current percentage figure required, and just by altering this one cell would update all the figures in the column. Help please.