A magnetic storage platter has an areal recording density of $1.50 \text{ Terabits per square inch}$ ($\text{Tb/in}^2$). Express this density in decimal Gigabytes per square millimeter ($\text{GB/mm}^2$). (Note: $1 \text{ Terabit} = 10^{12} \text{ bits}$, $1 \text{ Gigabyte} = 10^9 \text{ bytes}$, $1 \text{ byte} = 8 \text{ bits}$, and $1 \text{ inch} = 25.4 \text{ mm}$)