Matt's son, Zach, turned $10$ years old today. He plans to attend GSU. Matt expects tuition to be $$20,000$ per year by the time Zach starts GSU. Tuition payments are due on Zach's $18$th$,19$th$,20$th and $21$st birthdays. Matt plans to make deposits into Zach's college fund today and on every birthday until Zach turns $16.$ If the college funds earns $5\%$ then the deposits must be $$\_\_\_\_\_\_\_\_.$