H&M currently has sales of $10$ million a year, with a stock level of $25\%$ of sales. The annual holding cost for the stock is $20\%$ of the value. Operating costs $($excluding the cost of stocks$)$ are $7\mathrm{.}5$ million a year and other assets are valued at $20$ million. What is the current return on assets? How does this change if stock levels are reduced to $20\%$ of sales?