[ckissick]

My idea only works if there is an integer tag, like "INT".

In column G, the first line is 7.0. From there on, you create an IF statement in column G that says the interest rate is the cell above + 0.1, IF the cell for years (column B) divided by 5 is an integer, or else it's the column above plus zero. Every time you get an integer, it will go up by 0.1 and stay that way until the next integer.