Suppose operation $x$ feeds directly into operation $Y.$ All of $x\text{'}$s output goes to $Y,$ and $Y$ has no other operations feeding into it$.$ X has a design capacity of $80$ units per hour and an effective capacity of $72$ units per hour. $Y$ has a design capacity of $100$ units per hour. What is Y$\text{'}$s maximum possible utilization?

$80$ percent

$90$ percent

$72$ percent

$60$ percent

$70$ percent