Suppose that during a given year, 15% of all untenured processors leave a university (they are fired or find another job), and 15% are given tenure. Also assume that during each year, 5% of all tenured professors leave the university (via retirement or finding another job). If the university wants to have a faculty consisting of 200 untenured and 500 tenured professors, how many tenured and untenured professors should be hired each year?