The grantee shall extend its cable system and make cable service available to every existing residentially zoned area within the franchise area and within 6 months for newly annexed areas, whenever the density of at least 20 residential dwelling units per cable plant mile, as measured from the existing facilities of grantee’s cable system in the franchise area. For purposes of this section, density per cable mile shall be computed by dividing the number of residential dwelling units in the area by length, in miles or fractions thereof, of the total length of aerial or underground cable necessary to make service available to the residential dwelling units in the area in accordance with the grantee’s system design parameters. The cable length shall be measured from the nearest point that is located within the public ways. The total cable length shall exclude the drop necessary to serve individual subscriber premises. In the cases where residential density does not meet the density requirement, consideration will be made for line extensions based on a cost share basis as may be specified in the franchise agreement. The grantee may not otherwise discriminate against low income or low-density areas. For good cause, the grantee may request and the Town Manager may grant reasonable extension of time, within which to provide services to those areas with less than 20 homes per plant mile.