The return on assets using borrowed money, called leveraged return, is given by
$$L=\frac{Y-(1-D) R}{D}$$
where $Y$ is the return on the asset, $R$ is the cost of borrowed money, and $D$ is the percentage of money the investor must put down to secure the loan. Leanne wants to buy a bond with money that is borrowed from a bank. The bank requires her to pay $20 \%$ in cash to secure the loan. Find the approximate change in the leveraged return on the bond if the return on the bond changes from $6 \% /$ year to $6.5 \% /$ year and the cost of the borrowed money changes from $5 \% /$ year to $5.2 \%$/year.