In B-1 business districts the only uses which may hereafter be established are those permitted in the A-2 residential districts and in addition, the following:
Animal hospitals.
Commercial swimming pools.
Greenhouses.
Nurseries.
Professional and business offices.
Residential apartments and duplex or group houses at the rate of not more than one living unit for each two thousand five hundred (2,500) square feet of lot or building plot.
Restaurants.
Retail business and service establishments, excluding those listed in lower class districts. (1983 Code)