$ABCD$ is a quadrilateral such that $AD=9\ \text{cm}$, $BC=13\ \text{cm}$ and $\angle DAB=\angle BCD=90^\circ$. $P$ and $Q$ are two points on $AB$ and $CD$ respectively, such that $DQ:BP=1:2$ and $DQ$ is an integer. How many values can $DQ$ take, for which the maximum possible area of the quadrilateral $PBQD$ is $150\ \text{cm}^2$?