เมืองใดมีลูกค้าที่มีรหัสประเภท "Good Credit Rating" น้อยที่สุด
Which city has the least number of customers whose type code is "Good Credit Rating"?
customers = {'town_city': [], 'customer_type_code': []}
customers[customers['customer_type_code'] == 'Good Credit Rating']['town_city'].value_counts().idxmin()