List down the number of inhabitants of customers with a divorced marital status and older than 50 years old.
number of inhabitants refers to INHABITANTS_K; older than 50 years old refers to age < 50; MARITAL_STATUS = 'Divorced;
SELECT COUNT(T1.ID) FROM Customers AS T1 INNER JOIN Demog AS T2 ON T1.GEOID = T2.GEOID WHERE T1.MARITAL_STATUS = 'Divorced' AND T1.age < 50