(a) Not later than July 1, 1992, using the most current data available from the Department of Labor and the United States Department of Commerce, the commissioner shall rank and designate as less developed counties the lower 25 percent of all counties in this state using a combination of the following factors:

(1) Highest unemployment rate for the most recent 36 month period;

(2) Lowest per capita income for the most recent 36 month period;

(3) Highest percentage of residents whose income is below the poverty level according to the most recent data available; and

(4) Average weekly manufacturing wage according to the most recent data available.

(b) The commissioner shall be authorized to include in the designation provided for in subsection (a) of this Code section any county which, in the opinion of the commissioner of community affairs, undergoes a sudden and severe period of economic distress caused by the closing of one or more business enterprises located in such county. No designation made pursuant to this subsection shall operate to displace or remove any other county previously designated as a less developed area.