Why does the RIY increase with a greater % in cash?

With the end projection calculations, the cash account growth rate is based on the same rate as the rest of the portfolio so a consistent rate is being applied across all platforms and providers being compared.  However, the RIY calculation on any cash element is actually using the growth rate we are supplied by the platforms for the interest rate distributed on the cash account. This therefore can differ by provider and hence can cause changes in the RIY results.  This is more notable when a large percentage has been put into cash.