Amendment sought to revise the income mix of public housing units by requiring that not less than 40 percent shall be occupied by families whose incomes does not exceed 30 percent of the area median income; and not less than 90 percent shall be occupied by families whose incomes do not exceed 60 percent of the median income for the area with the option to reduce to 80 percent occupancy if such a reduction would enhance the viability of the housing development.